The other one of the three seats that Democrats mishandled is in South Dakota, where Democrats once held hopes for contesting the seat. Reid aggressively worked to recruit former Rep. Stephanie Herseth Sandlin in the race, because she was one of the few Democrats who could run a competitive race in the conservative state. But Reid was unable to persuade former Daschle aide Rick Weiland to drop out of the race, and Herseth Sandlin passed on the contest. Annoyed by the outcome, Reid went so far as to criticize his own party’s candidate even after he locked up the nomination.

The races show that the Democratic establishment, like their GOP counterparts, can misfire when trying to control events from Washington. Reid overestimated the level of support Walsh had in his home state, and he didn’t do enough vetting to reveal his plagiarism problems. And in South Dakota, Reid underestimated the depth of liberal grassroots discontent toward Herseth Sandlin, who was accused of being a moderate sellout by the party’s small but vocal base.

Reid’s struggles haven’t been limited to the Democratic side. He’s also failed to achieve one of his signature accomplishments in 2010 and 2012—getting Republicans to nominate their weakest candidates by meddling in certain primaries. One of Reid’s most successful interventions came on his own behalf in 2010, when his campaign attacked his most credible challenger, Sue Lowden, during the primary. Republicans ended up nominating state Assemblywoman Sharron Angle, an archconservative who predictably ran a disastrous campaign. Democrats repeated the tactic in Missouri in 2012, with a Reid-aligned super PAC airing ads in the primary that hit wealthy businessman John Brunner, the GOP’s favored challenger to Sen. Claire McCaskill. Todd Akin won the closely contested nomination, and a once-doomed McCaskill cruised to victory.