The events of the past two weeks have taken a lot of the suspense out of the outcome of the presidential race, unless you're the kind of person who is fascinated by the question of whether normally "red" states like Arizona and Georgia will actually flip into the Democratic column this year. (Full disclosure: I am that kind of person.) Comebacks are possible in politics, but the Trump campaign seems particularly ill-equipped to make one—especially with damaging revelations and counterproductive strategies emerging on what now seems like an hourly basis.
A decisive Republican loss in the presidential contest would probably be accompanied by a switch in party control of the Senate. All but one of the competitive Senate races this year are for seats now held by Republican incumbents, and a net change of four seats would be sufficient to produce a Democratic majority in the event of a Hillary Clinton victory (since the vice president would break a 50-50 tie). Most Republican Senate candidates are likely to outrun Donald Trump in their home states, but GOP nominees in electoral battlegrounds like Pennsylvania and New Hampshire will find it difficult to attract enough crossover support from Clinton voters to prevail over a national Democratic wave, should it appear. If Trump demoralizes enough of his own party's supporters that Republican turnout falls across the nation, Democrats could wind up winning a near-sweep of the key Senate races.
Compared to the Senate, Republican prospects in the House look considerably brighter. It's difficult to know exactly how vulnerable the Republican House majority is in the wake of Trump's latest problems; we suffer from a lack of good survey data on congressional races (media polling budgets are getting tighter, and the presidential race has consumed virtually all of the attention this year). But Republicans have the twin advantages of a structural edge in the configuration of House districts and a superior crop of candidates compared to Democrats, who failed to recruit a large number of high-quality challengers. A pro-Democratic electoral tide would need to be quite massive indeed to flip the 30 seats necessary to shift party control of the House.
And yet Paul Ryan is in a much tougher position, politically speaking, than Mitch McConnell.
Even if the House GOP ultimately retains its majority, the party's likely margin of control narrows by the day with each new Trump mishap. Ryan is already operating with little room for error, as he is situated between the hard-line House Freedom Caucus on one side and the opposition Democrats on the other. A Democratic victory in the presidential race would mean that Ryan would, like his predecessor John Boehner, need to cut bipartisan deals in order to fund the government—which would inevitably leave him open, as Boehner was, to criticism from party purists that he did not sufficiently defend conservative principles. The fact that the new Democratic president would be a figure uniquely loathed on the popular right—especially after a presidential campaign in which the Republican opposition characterized her as a literal criminal—further threatens Ryan's ability to hold off such attacks.
Boehner's departure from the speakership last year was prompted by the unique constitutional requirement that the Speaker be elected by a majority vote of the full House, which gives any dissident faction of the majority party tremendous procedural leverage. Even if Ryan were able to win an initial vote for Speaker this coming January, he would serve under a constant threat of defenestration from an purist right motivated by fierce antipathy to Hillary Clinton and to any Republican who faces her with less than total opposition.
By comparison, McConnell has it easy. To be sure, he is more likely than Ryan to lose his governing majority in this election. But if the worst happens, he will slip smoothly back into his role as minority leader, leading filibusters against Democratic legislation and waiting for the 2018 midterms, which will provide Senate Republicans with a very favorable set of vulnerable Democratic seats.
Ryan was famously reluctant to seek the speakership upon Boehner's resignation. When he was finally prevailed upon to do so, he probably assumed that there was a fairly good chance of a Republican presidential victory in 2016—which would both hand him an opportunity to implement his national policy agenda and relieve him of responsibility for leading the opposition to a Democratic administration.
Today, those hopes have faded away entirely. Ryan as much as conceded the presidential race in a conference call with House Republicans earlier this week, telling them to do whatever they needed to do in order to save their own seats. Even that admission earned him some blowback from conservative purists within his own caucus—a preview of what may turn out to be an even uglier conflict within the Republican Party if Trump goes down to defeat. If Ryan is handed a narrow majority on November 8 along with four guaranteed years of a Democratic president, he will need to draw upon all his political acumen in order to prevent suffering the same fate as John Boehner.