The left played defense in the wake of the loss, insisting that it is unwise to compare the two countries an ocean apart, and that the moderates bashing them had never been held accountable for Hillary Clinton’s 2016 loss. Plus, they pointed out, Sanders and Warren have far higher favorability ratings than the unpopular Corbyn.

But because Sanders had praised Corbyn in the past and his current and former aides have boosted him, Labour’s monumental defeat trained attention onto him in particular, even from some fellow progressives.

“Corbyn was basically a satellite project for Bernie world. If there is one lesson to be gleaned from the devastating loss across the pond, it’s that we need more than just soaring rhetoric backed up by bravado of organizing,” said Murshed Zaheed, a Megaphone Strategies partner and former Harry Reid aide backing Warren. “We need to have leaders who have crystal-clear analysis of how to solve problems and leverage power to achieve those solutions. Corbyn never appeared to be a candidate with any sound plans on how to move U.K. forward.”