But less attention has been paid to how the shrinking number of Democratic officeholders in the House and in statewide offices is affecting the party’s Senate races. It’s awfully unusual to see how dependent Democrats are in relying on former losing candidates as their standard-bearers in 2016. Wisconsin’s Russ Feingold, Pennsylvania’s Joe Sestak, Indiana’s Baron Hill, and Ohio’s Ted Strickland all ran underwhelming campaigns in losing office in 2010—and are looking to return to politics six years later. Party officials are courting former Sen. Kay Hagan of North Carolina to make a comeback bid, despite mediocre favorability ratings and the fact that she lost a race just months ago that most had expected her to win. All told, more than half of the Democrats’ Senate challengers in 2016 are comeback candidates.

On one hand, most of these candidates are the best choices Democrats have. Feingold and Strickland are running ahead of GOP Sens. Ron Johnson and Rob Portman in recent polls. Hill and Hagan boast proven crossover appeal in GOP-leaning states that would be challenging pickups. Their presence in the race gives the party a fighting chance to retake the Senate.

But look more closely, and the reliance on former failures is a direct result of the party having no one else to turn to. If the brand-name challengers didn’t run, the roster of up-and-coming prospects in the respective states is short. They’re also facing an ominous historical reality that only two defeated senators have successfully returned to the upper chamber in the last six decades. As political analyst Stu Rothenberg put it, they’re asking “voters to rehire them for a job from which they were fired.” Senate Democrats are relying on these repeat candidates for the exact same reason that Democrats are comfortable with anointing Hillary Clinton for their presidential nomination: There aren’t any better alternatives.