Senate Majority Leader Mitch McConnell of Ky., speaks with reporters after walking off the Senate floor, Thursday, Dec. 19, 2019, on Capitol Hill in Washington. Credit: Patrick Semansky | AP

Senate Majority Leader Mitch McConnell, R-Kentucky, might not care about his oath as an impeachment juror or the appearance of unfairness generated if he disallows witnesses or the judgment of history, but he cares very much about keeping his seat and the Republican majority. If he senses that either is at risk, he might think twice about assisting President Donald Trump’s efforts to block witnesses at his impeachment trial. McConnell might even take up some of those “275 bipartisan bills” that have passed the House but still await consideration by the Senate.

McConnell might consult a map and some polling data. The map will show, according to Jennifer Duffy of the Cook Political Report, that “Democrats appear to have expanded the playing field enough to put Republicans’ majority at risk.”

Duffy writes:

“For Republican U.S. Sens. Martha McSally in Arizona, [Cory] Gardner in Colorado and Susan Collins in Maine, a vote to remove Trump from office is likely to earn them very credible primary opposition, something that would hurt their reelection efforts. But, a vote to acquit Trump doesn’t help them appeal to the kind of college-educated suburban voters they need to win. For these four incumbents, there is no easy answer, making the possibility that there might not even be a Senate trial seem appealing.”

On top of that, Democrats have outspent Republicans “$21.9 million to $10.6 million, according to data provided by Advertising Analytics.” In Maine alone, as much as $55 million will get spent, most on anti-Collins ads.

In short, “It appears that there will be at least five GOP-held seats in play, with a chance that Democrats could add one or two more. This puts Democrats in a position to win the majority, even if they lose Alabama and/or Michigan. This is not to suggest that Democrats will win the majority, only that their prospects are considerably better today than they were five months ago.”

McConnell might consider how difficult it will be for moderates such as Collins and Gardner to explain to voters not just voting to acquit Trump but voting to block key witnesses and evidence, which the vast percentage of Americans want to see.

While McConnell is mulling the burden he is putting on his members to participate in the Trump coverup, he might consider some of that legislation passed by the House that he (aka the “Grim Reaper”) buried. In a stack of 400 bills are hugely popular measures, including legislation for expanding background checks, controlling prescription drug costs and guaranteeing equal pay for women. McConnell is not taking up any of them – despite their overwhelming popularity.

Background checks garner support from 90 percent of Americans. On drug pricing, Kaiser Family Foundation polling finds a plurality of independents (47 percent) think Democrats will do a better job in controlling drug prices, and nearly 90 percent favor allowing the government to negotiate drug prices, something that is in a House-passed bill. As for women’s pay, Republicans currently face a vast gender gap. (In a recent Economist/YouGov poll, for instance, Democrats have an 8 point advantage in generic House polling; the gap is 17 points among women.)

In short, by announcing he is holding a sham trial and by refusing to take up a host of very popular measures, McConnell may be serving Trump’s interests. However, he also may be making a tough election year even tougher for his members. If he keeps this up, not only might a flock of his members lose, but he could be toppled from his perch as majority leader. He might consider showing more concern for his at-risk members by taking his oath as juror and his regular job — legislating — more seriously.

Jennifer Rubin writes reported opinion for The Washington Post. Follow her @JRubinBlogger.