The answer lies in the incentives Republicans face in the long and short terms. The modern GOP, like the post-Nixon iteration of the party, could bounce back from removing a president and end up in a stronger position to resolve the ideological problems that plague it. But congressional Republicans also want to win reelection. That might end up outweighing all other considerations, including the judgment of history.
Republicans thinking of their own self-interest are right to worry. The immediate aftermath of Watergate and Richard M. Nixon’s resignation was an electoral disaster for Republicans. In 1974, Democrats won the midterms, beating Republicans in the House popular vote by 17 points, gaining a 61-vote majority in the Senate and a 291-member majority in the House. If Trump was removed, the GOP would probably also see deep losses.
But Republicans recovered from their post-Nixon slump relatively quickly. By 1981, Republicans had recouped their post-Watergate losses in the House and took control of the Senate. Watergate only barely showed up in presidential election results. Despite pardoning Nixon just two years earlier, President Gerald Ford only lost to Jimmy Carter by two points in 1976. And only four years after Ford’s defeat, Ronald Reagan beat Carter in a landslide, leading the party’s conservative faction to victory over the moderates and setting the Republican agenda for the next 35 years.
And in the aftermath of the Nixon era, Republicans were able to retool their ideological program. As Geoffrey Kabaservice, who has written a history of the Republican Party, has argued, conservatives took the time between Nixon’s removal and 1980 to build up their infrastructure, gain strength within the party and prepare the way for Reagan’s dominance of the party.
Some modern Republicans might long to push a similar reset button. Trump won the 2016 primary by championing immigration restrictionism, promising universal health-care coverage, claiming that he’d basically chuck fiscal conservatism, criticizing George W. Bush’s invasion of Iraq and generally denying major tenets of conservative philosophy. But thus far, he has failed to replace Reagan-ism with any sort of consistent, coherent mode of thinking. Many elected Republicans likely would prefer governing and reworking conservatism under a President Mike Pence, who understands their worldview and wouldn’t demand constant bootlicking.
In the Senate, the calculus is only slightly different. Democrats need at least 20 Republicans to get the votes they need to convict Trump. A few GOP senators might consider joining them: Susan Collins and Cory Gardner need Democratic votes in their swing states, and Mitt Romney’s Mormon base is conservative and Trump-skeptical. But many will run fast in the opposite direction rather than risk being primaried by an opponent from the pro-Trump grass-roots.
And Trump, unlike Nixon, has only a loose, transactional relationship with his party that makes him less likely to make life easier for congressional Republicans. He could threaten incumbent senators, telling them he will back their challenger if they vote against him. And even if Senate Republicans worked with Democrats to quickly remove the president, ex-President Trump could endorse vengeance-fueled primary challengers by tweet while watching Fox News at Mar-a-Lago. These threats alone, credible or not, might be enough to keep Republicans in line.
Long-term self-interest might also point top Republicans toward Trump, especially in the Senate. As others have repeatedly noted, Ronald Reagan, a Nixon ally, won the 1980 Republican presidential primary while former Senate majority leader Howard Baker, famous for his “What did the president know, and when did he know it?” line, barely registered. After pardoning Nixon, Ford lost some ground among Republicans but still had more than half of the party behind him. Many Nixon allies proved their party loyalty by sticking with the president far into the impeachment process. And Republicans who want to woo the Trumpian pieces of the Republican base (or at least stay acceptable to them) might make a similar choice.
Some Republicans might feel pulled in the opposite direction by some combination of principles and praise. They might want to impeach or remove Trump, soak up praise from the media and earn an honored place in the history books. But history books don’t vote in primaries. And modern Republicans, like every other group of politicians, care about keeping their jobs.