A bloc of moderate Senate Democrats successfully secured significant, last-minute changes to the $1.9 trillion coronavirus relief bill Friday, marking an early attempt to flex their new political muscle and shape President Biden’s economic agenda on Capitol Hill.

With the Senate equally divided, the party’s moderates sought to portray themselves amid the stimulus debate as a fiscally restrained counterpoint to liberals — even as they stood with Biden on the need for new emergency aid. But their tactics still threatened to open new political rifts in the party and leave perhaps millions of Americans unable to obtain checks and other support they might have otherwise received.

In recent days, the moderates have narrowed federal stimulus payments, brokered a tentative deal to revamp future unemployment benefits, and halted a renewed effort to raise the federal minimum wage to $15 an hour. The changes mark a break from the bill approved in the House, where lawmakers fought vigorously for their version of the stimulus out of a belief that the 2020 election had given them a mandate to deliver economic reforms that had flagged under President Donald Trump….