We face momentous choices in the upcoming 2012 presidential election, with one party seeking radical cuts in government and taxes and the other trying desperately to defend social spending and a positive role for government. Twelve years from now, in the 2024 election cycle, are voters likely to be confronted with the same choices? Or will our parties and their politics have changed significantly to accommodate a changing country?

I believe the latter will be the case and, hard as it may be to believe today, these changes will be largely for the better. Start with shifting demographics. Another 12 years of change is likely to increase the minority share of voters by another six points. If minorities are, as expected, 28 percent of voters in the 2012 election, that would put the minority share of voters in 2024 at 34 percent.

The other side of this will be a continuing drop in the share of white voters. This drop is likely to come entirely from the ongoing decline in the relatively conservative white working class. Other changes that will affect the white population include rises in the shares of single, professional, and secular voters among whites, and, critically, ongoing generational replacement as millennial voters, those now between the ages of 12 and 34, take the place of the oldest cohort of voters.

In sum, then, the electorate of 2024 will be marked by a substantial increase in the share of minority voters, who lean strongly Democratic, and significant shifts within the declining white population that should serve to liberalize that population. This casts considerable doubt on the viability of current GOP strategy that cedes the minority vote to the Democrats and relies on squeezing an ever-higher share of votes from whites. Indeed, this approach seems a perfect candidate for Stein’s Law: If something can’t go on forever, it won’t.

Republicans will eventually—and very reluctantly—bow to electoral reality. They will compete much more vigorously for minority, particularly Hispanic, votes, and they will seek to broaden their appeal to younger and more moderate white voters. This will involve not just moving away from hard-line positions on social issues like immigration and gay marriage but also jettisoning a reflexive opposition to social spending and the tax increases that will be necessary to support it. Expect more David Frum and less Grover Norquist.

It’s not just the Republicans who are likely to change but Democrats as well. The ongoing war within the party about whether to emphasize deficit reduction or growth and jobs will be resolved in favor of growth. The deficit problem is far less serious than today’s conventional wisdom has it and, as Ezra Klein notes, there are really only two choices on the deficit: “Do something to solve it or do nothing [letting current tax cuts expire] and let that solve it.” The problem of growth, as we move sluggishly out of the Great Recession, is actually far more difficult to solve and far more important.

This is true both economically and politically. The unifying thread running through Democrats’ diverse emerging constituencies is their aspirational nature. They tend either to be labor-market outsiders who aspire to become insiders, or holders of relatively large amounts of human capital who aspire to high economic mobility and a high quality of life. This necessitates a strong role for government, but one that shifts progressive policy priorities from security to opportunity. The latter entails an emphasis on policies like: the acquisition and use of education; the development of new economic sectors like biotechnology and clean energy that can provide high-skill, high-wage jobs; investment in infrastructure that can support rising economic sectors and the transition to a green economy; the provision of effective public services from green spaces to transportation; and the achievement and maintenance of full employment.

Little of this is possible without relatively fast and evenly distributed economic growth. Yet over the last several decades, Democrats have become inured to slow and unevenly distributed growth and a sluggish labor market, preferring to concentrate on defending existing benefits (e.g., Medicare and Social Security) or, worse, privileging fiscal responsibility and deficit reduction over growth.

Given the Democrats’ emerging coalition, that approach is not sustainable and it will change. The development and implementation of a new progressive growth model will be central to Democrats’ identity by 2024 and much of the debate between the parties will be about whether that or a conservative alternative with a more limited, though still significant, role for government is more effective. For example, a Democratic presidential candidate in 2024 might be arguing for a dramatic expansion of the American educational system—say, making post-secondary education universal—while a Republican candidate might also advocate expansion, but a more limited one combining modest student subsidies with tax breaks for profit-making schools. But the days when Republicans could stand pat on cutting taxes and Democrats on defending Social Security and Medicare will be over.