Regular readers of this column are familiar with the case frequently made here, that Democrats face a difficult challenge in next year’s elections as they try to defend the White House and their scant 51-49 edge in the Senate, while winning enough House seats to recapture a lower-chamber majority. The presidency was determined by the narrowest of margins in 2020, with President Biden carrying five out of the six states that were decided by 1.5 percentage points or less, almost a reversal of former President Trump’s win in four of the six decided that narrowly four years earlier. In one election, Trump caught almost all of the breaks; in the next, Biden did.

As for the Senate, defending that tiny edge seemed difficult enough before Sen. Joe Manchin’s retirement announcement last month. Now, his West Virginia seat will certainly flip into the GOP column. Democrats also have five incumbents up for reelection in states that Trump carried either twice (Ohio and Montana) or once (Arizona, Pennsylvania, and Wisconsin). In Arizona, Sen. Kyrsten Sinema was elected to the House and Senate

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