A long time ago, in a galaxy far, far away, Newt Gingrich was a moderate Republican. Few remember today that back in 1968 he campaigned in the South for none other than New York Governor Nelson Rockefeller. In his first bids for electoral office, Gingrich was twice defeated as the moderate challenger to a segregationist Democrat. Once in Congress, he helped found the Conservative Opportunity Society, but he still portrayed himself as a “Theodore Roosevelt Republican,” never quite renouncing his academic background in favor of a down-and-dirty populism. When he ascended to the leadership of the House in the late 1980s, he did so by courting the support of party moderates. “There’s no question that I would not be House Republican whip if activists in the moderate wing had not supported me,” he reflected after his election. Even in 1989, after shifting to the right, he continued to identify with “the classic moderate wing of the party, where, as a former Rockefeller state chairman, I’ve spent most of my life.”

How times have changed. Today’s Gingrich—not to mention the Gingrich of 1994—would have been unrecognizable to the man who backed Rocky in 1968. His shift is a marker of political polarization and the transformation of the Republican Party into a fiercely ideological hard-right party by almost every measure. In 2010, for example, National Journal found that every Senate Republican had a voting record more conservative than every Democrat. Politicians once seen as moderates have been driven from the Republican Party, either losing elections to conservatives or simply switching parties. And many of those who once deemed themselves moderate—like Newt Skywalker, as he was known back in the day for his space-age techno-geek’s support for “Star Wars” and NASA—have shifted inexorably to the right. Conservatism itself is more extreme than it used to be.

In Rule and Ruin, Geoffrey Kabaservice treats the demise of the Republican moderates as a gripping historical mystery. What happened to the “vital center”? The culprit, he argues, is “the transformation of the Republican Party over the past half-century into a monolithically conservative organization.” That shift has brought us the “vicious and violent” tone of our discourse and the “extreme, antagonistic, uncompromising and ineffectual” nature of our politics.

History is written not only by but about the winners, and recent years have seen no shortage of books about the rise of the conservative movement in postwar America. Historians like Lisa McGirr, Rick Perlstein, and Thomas Frank have analyzed its ideas, organization, financing, strategies, and social base. They have told the stories of grassroots conservatives, Phyllis Schlafly, the John Birch Society, conservative media, Barry Goldwater, and the many ways that Reagan’s election was anticipated long before 1980. Yet for all the thousands of pages that have been written about postwar conservatism, the fierce battles within the Republican Party itself have gotten much less attention, and historians have forgotten the extent to which conservative activists focused their energy on capturing the Republican Party.

For this reason, almost no one has written about the moderate Republicans who challenged conservatives for control of the party. In Rule and Ruin, Kabaservice sets out to overturn the conventional wisdom about the moderates—to argue that they exercised influence far longer than people realized, that they actually should get a good deal of credit for many of the liberal reforms of the 1960s, and that the most far-thinking among them sought for many years to fight back against the conservative onslaught and to reinvent Republicanism. An independent scholar whose previous book, The Guardians, treated Yale University President Kingman Brewster and his circle as exemplars of the peculiar liberalism of the postwar years, Kabaservice is well positioned to look at the decline of the Republican moderates. But his fascinating narrative history is more than a postmortem; indeed, it is a passionate call to revive the creed of moderate Republicanism. Beneath the history is an undercurrent of loss and longing for a political establishment that once was and is no more.

Kabaservice starts his book in 1960, with the Republican Party convention that nominated Richard Nixon as its candidate. By that time, Republicans were already deeply divided about both strategy and ideology. The party had been split in the past, between the “Old Guard” politics of Ohio Senator Robert Taft and the moderate Republicanism of New York Governor Thomas Dewey and President Dwight D. Eisenhower. Each in his own way, both Dewey and Eisenhower tried to breathe new life into Republicanism, showing that the creed once associated with Herbert Hoover and the laissez-faire of the 1920s could still be relevant after the Great Depression, that it could “rationalize and reform the New Deal rather than repeal it.” Along with their intellectuals, they developed an approach to social policy that emphasized support for business, individual liberties, economic incentives, and gradual reforms, but not an absolute anti-government stance or paranoid anti-communism.

There were some vehicles for this kind of Republicanism, including a magazine called Confluence that in 1952 counted among its editors a Harvard graduate student named Henry Kissinger. Kissinger was sharply critical of the American right, saying that “most American conservatives are Manchester liberals, in my opinion, or populists. I don’t even consider them conservatives.” But not even Taft, though his moniker was “Mr. Conservative,” was a purist—he supported various New Deal positions, never affected a populist stance, and did not approach policy through the lens of ideology.

By the end of the 1950s, though, a new mobilization of the right was starting to make itself felt within the Republican Party. These conservatives—who had been awakened initially by Joseph McCarthy, and who in 1960 lined up to draft Barry Goldwater for the nomination, impressed by his hostility to organized labor and his denunciation of Eisenhower’s “dime store New Deal”—believed that their side lost elections because they did not offer a sufficiently clear ideological alternative to liberalism. Success would only come—and would only matter—if the Republican Party stood for clear principles and could be purified of its heretics.

They were countered by another new force: that of “progressive” Republicans, who wanted to claim the Republican Party as the party of the civil-rights movement (untainted by the Democratic Party’s reliance on segregationists in the South) and of national reform in the tradition of Teddy Roosevelt. The earlier moderate Republicans, following Eisenhower, had relied on appeals to traditional authority; the progressives, by contrast, recognized the need to counter the right by actively organizing within the party. In 1960, Kabaservice argues, the progressive and moderate Republicans, with standard-bearers like Jacob Javits, Gerald Ford, and Rockefeller, looked at least as strong as the conservatives. They had intellectual organizations, they had financial support, they had deep citizens’ groups to elect Republican candidates in 1948 and 1952, and they had a political strategy.

The moderate Republicans, Kabaservice notes, “have to be counted among history’s losers, but this is not a history without heroes.” The central protagonists of Rule and Ruin are those Republicans who sought actively to find ways to build an intellectual and political movement around their moderate cause. In the spring of 1961, Tom Hayden—then a junior at the University of Michigan—wrote an article for the annual college issue of Mademoiselle called “Who Are the Student Boat-Rockers?” Alongside the left-wing Students for a Democratic Society and the right-wing Young Americans for Freedom, Hayden described Advance, a magazine founded by two Harvard undergraduates, Bruce Chapman and George Gilder, who wanted to promote progressive Republicanism. The journal sought to develop a new political philosophy for modern America: one that “borrows freely from the best of ‘conservatism’ and ‘liberalism’ and whose essence is not mere moderation.”

Both Gilder and Chapman would subsequently move to the right, with Gilder, in particular, becoming an ardent anti-feminist and a prominent conservative writer, publishing his best-selling defense of supply-side economics, Wealth and Poverty, in 1981. Throughout the 1960s, though, he and Chapman were at the head of the efforts to promote the progressive cause within the Republican Party. Advance got a good deal of attention for its attacks on Republican negativism and its claim that the best way forward would be for the Republican Party to draw on its abolitionist tradition and become the party of civil rights, the “nation’s most important domestic issue,” rather than adopt what would become known as the Southern strategy. For all its positive press, the journal folded in 1963 for lack of funds, but it did help to spawn the Ripon Society—named for the Ripon, Wisconsin, birthplace of the Republican Party—an intellectual and political club for moderate Republicans that sought to define a vision for the party that could challenge its popular image “as a party of obstruction and negativism.”

Rule and Ruin also tells the stories of dozens of moderate Republicans in Congress who provided vital support for key pieces of liberal legislation such as the Civil Rights Act of 1964. Among them were Senator Thomas Kuchel of California, whose political career was undone by Bircher allegations of homosexuality; Senator Charles Percy of Illinois, whose office wound up working with the Blackstone Rangers, one of the largest African-American street gangs in Chicago, in an effort to find solutions to urban poverty; Wisconsin Representative William Steiger, who was one of the authors of the act that created the Occupational Safety and Health Administration; and Ohio Representative Frank Bow, who proposed an alternative to Medicare that involved using tax incentives and government funds to subsidize the purchase of private health insurance.

Well-known moderates such as New York Mayor John Lindsay, Pennsylvania Governor William Scranton, and, of course, George Romney, Michigan governor and father of Mitt, all make appearances—as, more surprisingly, does one young representative from Chicago’s northern suburbs, Donald Rumsfeld, who was a disciple of Missouri moderate Thomas Curtis, and who wrote in the wake of Goldwater’s defeat in 1964 that the House Republicans needed to make the GOP a “reasonable, constructive, and effective force.” Throughout, Kabaservice makes the case that these Republicans were not simply imitating Democrats, but advancing their own distinctive political philosophy. They were sympathetic to private enterprise and hostile to centralized authority, embracing the use of incentives to achieve social ends. But in contrast to today’s ideologues, they believed there was a role for social policy and for government; they were not reflexively opposed to taxes and the state; and they were not overly concerned about social issues related to sexuality, marriage, and the family.

The story comes to its climax in the presidency of Richard Nixon. Nixon embodied the contradictions of the Republican Party. He drew on the Ripon Society network, appointing more than a dozen of its members to positions in the Administration, even as he also relied on the “Syndicate,” as the conservative organization within the Young Republicans was known. This reliance on the moderates, in Kabaservice’s view, is why Nixon was able to pass so much legislation that is often viewed as liberal, such as the Occupational Safety and Health Act and the Environmental Protection Act. Nixon’s “New Federalism”—which introduced revenue sharing between federal and state governments, giving states more power in the implementation of federal programs—was celebrated by the moderates. But at the end of the day, Nixon’s hostility toward “the Establishment” extended to the intellectuals of the Ripon Society and the moderate movement. He ultimately embraced the Southern strategy, sought to form alliances with working-class conservatives, and gave up on the “elitists” in the Republican Party. They would never again exercise such power in a presidential administration.

This did not mean the end of the moderate tradition in the GOP. There were some attempts to press the moderate cause in the early 1970s. In what seems a bit of a stretch, Kabaservice identifies supply-side economics as a program that received support from moderates and that shares some aspects of their worldview. In its original formulation by political leaders such as New York Representative Jack Kemp, he argues, supply-side was not necessarily anti-government; instead, its advocates argued that through lowering taxes the state could actually generate more revenues, thus avoiding austerity measures that would create social conflicts. The last chapter of the book moves quickly through the Reagan years, showing how the ranks of the moderates thinned over time, as they left the party to become independents or Democrats, or were defeated by the more organized right wing of the party.

The rise of the Christian right and the Moral Majority brought a new religiosity and ever-more-fervent anti-intellectualism to the conservative cause. (There’s a great story about L. Brent Bozell, the National Review editor and ghostwriter of Barry Goldwater’s The Conscience of a Conservative, leading the charge against abortion in 1970 under the banner of a pro-Franco group by bashing the windows of a health clinic at George Washington University with a five-foot-tall wooden cross.) Even Goldwater would ultimately be denounced as a “Republican in Name Only.” Kabaservice concludes with the 2010 defeat of Republican moderate Mike Castle in Delaware’s Senate primary by Tea Party candidate Christine O’Donnell, whose populist campaign included her infamous television ad in which she said, “I’m not a witch. I’m you”—a sign for Kabaservice of how much the conservative movement has lowered the standards of political debate.

Rule and Ruin builds a powerful case for the historical importance of the moderate Republicans and the contests within the postwar Republican Party. Yet at the same time, this illuminating book leaves the reader crying out for some deeper explanation of what happened to the moderate tradition. Why has it disappeared?

Kabaservice describes how the moderates failed to think politically. They would not stoop to grassroots organizing. Their money men pulled out when they stood to lose too much. Nelson Rockefeller, who could have funded a flotilla of think tanks, instead poured his ample resources into his own political cause. Most of all, the moderates simply did not care enough. Moderation, Kabaservice suggests, was necessarily hampered because a political creed that defines itself as pragmatic and intellectual will always be weaker than a politics of passion. In some ways, he views moderation as an attitude more than a particular set of positions—a skeptical, thoughtful, non-ideological politics, committed to governance and to using the state to deal with social problems. The titles of the book’s chapters are drawn from W.B. Yeats’s poem “The Second Coming,” with its description of the “rough beast” slouching toward Bethlehem: “The best lack all conviction, while the worst are full of passionate intensity.” The book has something of the tragic in it, telling the story of the undoing of gentle and intelligent men (and they were almost all men) whose very failure was that they clung to their moderation.

The moderate Republicans did accomplish much of which to be proud. Their support was—as Kabaservice argues—critical for the passage of the Civil Rights Act and the Voting Rights Act. Senators like Javits and John Sherman Cooper helped to end the Vietnam War by defunding it. The moderate force within the party did not decline easily or quickly, continuing for a long while to offer a real alternative to hard-line conservatism. Historians of the late twentieth century have at times treated the triumphs of conservatism as though these were foregone conclusions; Kabaservice shows how it was a fight all along the way, through the 1980s and beyond.

For all there is to admire about the moderates, though, it is not so easy to mourn their demise. The politics of passion that Kabaservice critiques was not driven by the romantic impulses of irresponsible youth; in reality, the consensus collapsed because it hid and protected much—segregation, poverty, the repression of the Cold War years—that was in fact not moderate at all.

Rule and Ruin also has little to say about the forces that have reshaped both political parties, such as the increasing political organization of business, the role of money in elections, the decline of unions, and, perhaps most important of all, the rise of an intellectual culture that has become increasingly skeptical of virtually any sort of collective action. Nor is there much discussion of the social world that spawned the mandarin-style politics of the liberal establishment Kabaservice chronicled in his previous book and of the liberal Republicans he writes about here. They all belonged to an elite that had been instructed in its obligations to rule—a profoundly different ethic from the hedge-fund gurus of today for whom there is no higher calling than self-interest, but a deeply problematic ethic in its own way.

Finally, despite its focus on the Republican Party’s hard-right turn, the underlying claim of Rule and Ruin is that political polarization, not the overall drift to the right of American politics, is the central problem that our country faces today. Surely the hard-right unity of the GOP is a critical part of this story. Yet one of the ironies of this rich and complex book is that, by its end, the Democrats under Bill Clinton helped speed the demise of the moderate Republicans, as the centrist Democratic Leadership Council began to advocate many of the pro-market ideas (such as welfare reform and charter schools) that GOP moderates had long championed. And it is those moderate ideas and that moderate politics that have helped to drive the widening inequality of the country by cutting taxes, deregulating finance, weakening unions, devolving federal authority to the local level, and endorsing the primacy of the market as a vehicle for righting social wrongs. For anything to change, the last thing we need is more of this. The real heroes of the civil rights movement and the movement against the Vietnam War were not, after all, the moderate Republicans, but the passionate advocates who fundamentally challenged the tenets of moderation by asking—indeed, demanding—that people take a stand.