At the beginning of the campaign, Republican senators made a cynical, if politically sensible, gamble: With many Republican voters holding allegiance to Trump as a litmus test, GOP lawmakers fell in line. They had a lot more to lose by breaking with the president than by working with him as a legislative partner. In January, as cameras rolled, McSally publicly attacked a CNN reporter as “a liberal hack,” the better to energize the base. Now she’s desperately trying to win back the very moderates she alienated with her hard-line rhetoric.

In the final stretch of the campaign, many Republicans will portray themselves as a check against a future Democratic government, but their own past partisanship will make it difficult to sell that pitch convincingly. Their best chance to salvage a narrow Senate majority is in North Carolina, where a late-breaking Democratic sex scandal has upended the race. But even if Democrats self-destruct in North Carolina, Republicans will still need to hang onto a growing roster of too-close-for-comfort red-state races in which Democrats are running strong, well-funded campaigns.

Here’s the grim reality for Republicans: The GOP path to holding the majority is narrow, even with the late-breaking sexcapades of North Carolina Democrat Cal Cunningham. Republicans are pessimistic about their ability to hold onto seats in Colorado, Arizona, and Maine, where the anti-Trump political environment has overwhelmed Republican incumbents. If Democrats lose Sen. Doug Jones’s seat in Alabama as expected, they would need to pick up one more Republican-held seat to win a working majority (assuming Joe Biden wins the presidential election and Kamala Harris would break any ties as vice president).