Jason Riley reports on the continuing struggles of Tom Cotton’s challenge to incumbent Sen. Mark Pryor in Arkansas’ Senate race:

For most of this year, the Senate race in Arkansas between incumbent Democrat Mark Pryor and GOP Rep. Tom Cotton has been neck and neck. But three polls since April 1 have shown Mr. Pryor with a double-digit lead.

The report notes that Pryor is managing to win the support of a third of the voters that disapprove of Obama, so he isn’t weighed down as much by Obama’s unpopularity in the state as Republicans assumed he would be. Cotton has run a shaky campaign, and in the last poll his unfavorability is slightly higher than his favorability. Dana Milbank notes that Cotton has been stressing his military service in his campaign ads, but this doesn’t seem to have helped him very much. It cannot help Cotton that he seems to be identified with Washington and with Congress specifically, and his hawkish foreign policy views are bound to make him less appealing at a time when most Americans are rejecting interventionist arguments.

Cotton was touted as one of the best of the GOP’s Senate recruits this cycle, and Pryor was considered to be extremely vulnerable. If Republicans can’t pick up a Senate seat in a midterm election year in a state where Obama is overwhelmingly disliked, it seems unlikely that they will gain control of the Senate. It also suggests that the party is struggling even in parts of the country in which it ought to be thriving, and it should serve as a warning that even relatively strong candidates aren’t able to compete when they are promoting deeply unpopular policies.