Bernie Sanders had an urgent plea at a meeting for Senate Democrats this week: We’re with you on this bipartisan bill, so you better be with us on our $3.5 trillion spending package, attendees said.

Shortly after Wednesday’s caucus meeting, Sanders called House Speaker Nancy Pelosi to reinforce her position of holding back the bipartisan deal until a massive domestic bill passes the Senate, according to a source familiar with the call…

As progressives praise Pelosi and make public threats to sink the bipartisan bill if she buckles, moderates are already urging the speaker to drop her blockade of the upper chamber’s infrastructure deal. It’s a conflict that will test the strength of Democrats’ House and Senate relations, with slim majorities spread out across a large ideological spectrum. And there’s always the danger that the longer the process drags out, the more likely one or both tracks might collapse.

“Strike while the iron’s hot,” said Rep. Elissa Slotkin (D-Mich.), one of the several dozen House centrists who have been pushing for swift action on the Senate deal across the Capitol. “If you get a deal, and if it’s significant money, don’t let it sit. It does not age well.”