Left-wing members of Congress are hardly afraid to break publicly with Joe Biden. They were the only Democrats to vote against the president’s bipartisan infrastructure bill in November 2021, insisting on a concurrent vote for a bigger social and climate policy bill. They have been outspoken in their demands for Biden to withhold additional aid to Israel until it ends its war in Gaza. And they were among the first voices blasting Biden for adopting a more centrist, enforcement-focused approach to the surge in migrants arriving at the U.S.-Mexico border.