While we were getting our list of 2020 Senate races together, we noticed that Tom Cotton, the Republican sleazeweevil from Arkansas, is running unopposed for reelection. Yeesh, Arkansas Democrats, we thought, it's a red state, but you should at least have tried. And then when we looked into it, we found that, in fact, there had indeed been a Democrat running against Cotton for a few months last year, a guy named Joshua Mahony. But Mahony dropped out of the race two hours after the November 17 filing deadline. Under Arkansas law, parties can only pick a new candidate after the filing period ends if their candidate dies or is seriously ill. That wasn't the case, so Tom Cotton is virtually guaranteed to roll to reelection without even having to contend with any speed bumps — while continuing to fundraise, to boot.

Now, to be sure, even a top-notch Democratic candidate would have a hard time in Arkansas, which has been dominated by increasingly right-leaning Republicans in recent years, to the point that many of the angriest political battles have been between traditional business-class conservatives and fire-breathing culture-wars righties. Mahony was a fairly weak candidate to start with, and probably had no business running for the Senate anyway. We suppose the best that can be said about how the whole mess played out is that it's a good cautionary tale: Don't go with a candidate who you haven't thoroughly vetted.