By Friday morning, the contours of the vote on witnesses seemed clear. Of the 53 Republicans in the Senate, 51 would oppose new witness testimony and evidence, with Sens. Mitt Romney (R-Utah) and Susan Collins (R-Maine) being the only two hold-outs. Other senators who seemed as though they might support the idea, like Sens. Lisa Murkowski (R-Alaska) and Lamar Alexander (R-Tenn.), announced their opposition to the move.
This seems, from a distance, somewhat surprising. Alexander, for example, is retiring; why wouldn’t he then join the stated concerns of Romney and Murkowski? And what about senators like Sens. Cory Gardner (R-Colo.) and Thom Tillis (R-N.C.), both of whom, like Collins, have tough reelection fights this November? Why weren’t they persuaded to share her moderate position?
To answer those questions, we should start with two key pieces of data that don’t involve the impeachment at all.
We covered this on Thursday night. Gallup’s annual average of presidential approval ratings, released on the first day of the impeachment trial, showed that the gap in views of Trump by party was wider than at any other point on record.
At the same, the gap in the average ideology of both parties’ Senate caucuses is similarly wider than at any prior point.
If we cross-reference those data — ideology versus support for Trump in each state, as measured by the 2016 vote — the Senate looks like this. (Sen. Kelly Loeffler (R-Ala.), recently appointed to the Senate, doesn’t have a voting record that allows for ideological analysis.)
You’ll notice quickly that there are several Democrats who represent strongly pro-Trump states, including Sens. Joe Manchin III (R-W.Va.) and Doug Jones (R-Ala.). But, so far, there’s been no indication that Democratic senators will break ranks and oppose new witnesses and information.
We can isolate the senators mentioned above to get a better sense of their political positions.
Collins stands out at lower left. Maine is a state that backed Hillary Clinton in 2016 and her politics are more moderate than the rest of her caucus. Alexander, by contrast, is from a much redder state. Gardner, Tillis and Sen. Martha McSally (R-Ariz.), who hopes in November to defend the seat to which she was appointed, are much less moderate than Collins even though they are from battleground states. Murkowski is from a much redder state.
Romney clearly stands out: he’s less moderate than Alexander or Collins and from a more pro-Trump state than Gardner or McSally. But he’s also built his recent political identity on skepticism of Trump, something that’s appreciated in Utah. No red state saw a bigger swing to the left than Utah in 2016, a function both of the fact that Romney was on the ballot in 2012 and of broad skepticism of Trump.
There’s another important factor at play here: how safe the senators feel. If we compare their last election results (looking at the two-party vote margin) with the 2016 vote in the state, the Senate looks like this.
Again separating out the potential swing senators:
(McSally isn’t included because her last Senate race was against Sen. Kyrsten Sinema (D-Ariz.), and she lost.)
Collins is in much safer territory than Gardner or Tillis, each of whom won narrowly in 2014. Murkowski is similarly safe — but not up for reelection anyway.
2014 was a year in which Republicans did well nationally, taking advantage of the recent pattern of off-cycle success for their party. 2020 may be different, with Democrats energized to come to the polls to vote against Trump. But Republicans, too, are energized — and Gardner and Tillis may be calculating that it makes more sense not to irritate Republicans in their states than to try to appeal to Democrats by voting against the president.
That idea brings us back to the chart with which we began. Trump is very popular with Republicans and very unpopular with Democrats. If you’re a swing-state Republican up for election this year, a decision that embracing your base is the better play isn’t hard to understand.
What the graphs above really show is which senators might have been in play. Those at the extremes — staunch conservatives from deep red states — weren’t. More moderate senators from more purple states, people up for reelection — these are where you might expect Democrats to be able to pick up votes.
In this case, they apparently didn’t pick up enough.