It’s hard to pick a standout, but the nomination of Sen. Jeff Sessions for attorney general has to one of Trump’s most worrisome picks for top posts in the new Administration. Session not only shares the President-elect’s loathsome politics (he signed onto the campaign early, when overt racism was one of the Trump’s few clear positions), but he also, unlike other administration picks, has the experience to run the Justice Department with disturbing efficacy. Even the muted Times report on his nomination hearings manages to convey some sense of urgency: Sessions will reportedly “assure” senators that he would be “willing” to resist any attempt by Trump to fulfill “incendiary campaign pledges.” The piece includes this singularly un-reassuring piece of advice: “Look for Democrats to try to use Mr. Sessions to frame the legal limits of a Trump presidency.”

Of course, we need better checks on Trump’s authoritarian wish-list than a promise from Jeff Sessions that he can muster the willingness to say “no” to his ideologically simpatico boss. In the past, many of these limits have come not only from the formal procedures and institutions of our legal and political system, but also from the complex set of informal norms which help govern any democracy. Some of these informal norms have loose enforcement mechanisms (such as shame), but others persist only so long as people agree to abide by them. The erosion of many of those norms made Trump’s rise possible in the first place; his presidency, even before its official start, has already attacked (and possibly destroyed) many more of them.

One of the basic tasks of the next four years will be to consistently resist the erosion of the norms which support American democracy, but the best way of achieving that goal won’t always be clear. Already Democrats are showing signs of struggle: witness President Obama’s barely concealed frustration at having to ensure a smooth and peaceful transition to the Trump administration, a perceived imperative driven by devotion to the very liberal-democratic order that is threatened by Trump and his legitimation by responsible elites. There may be no simple solution to the terrible task the outgoing President has been left with; it merely shows that over the next four years, Trump’s opponents will sometimes have to choose between unyielding fealty to norms and, at other times, a careful consideration of whether adherence to norms perversely undermines the values they stand for. The success of Trump and the radicalization of the GOP has consistently been enabled by both politicians and journalists who fethisize certain norms and, in so doing, undermine the deeper value or purpose for which the norms exist.

That’s why it’s reassuring that Senator Cory Booker has decided not only to oppose the nomination of Sessions for attorney general, but—in a move without precedent—to actually testify against his own colleague at the hearings. Booker’s move is unlikely to stop Sessions’s nomination, and most viewers won’t appreciate even its symbolic importance. But the Senate’s norms are among the most fastidiously observed in Washington, a fact from which Mitch McConnell developed one of his key strategic insights: Unilateral norm-breaking by Republicans could reap immense benefits, since precedent-bound Democrats would be unwilling to fight back in kind.

The unusual step of testifying against a sitting colleague, which is certain to bring public attention to the Sessions nomination, is a sign that the opponents of Trump’s agenda are starting to think strategically about when breaking with precedent is justifiable. The Trump years will present innumerable situations in which opponents of the President’s extremism and authoritarianism—which will often take the form of a disregard for norms and precedents—will have to choose whether to abide by norms themselves. Some situations will call for unyielding fealty to established practice; in others, preserving a norm may amount to merely observing some kind of formal decorum while allowing the value it stands for to wither away. Cory Booker has identified a norm to which loyal observation would, at this moment, prove perverse: It preserves nothing of the Senate’s dignity to behave as though this were a normal nomination for a normal administration. Hopefully others who are concerned about the direction of a Trump presidency are coming to the same realization, and are preparing for the difficult calls that undoubtedly await us.