“When is Leader McConnell going to schedule time for consideration of this and other climate change legislation?” asked Mr. Schumer, who is newly embracing climate change as an issue that appeals to younger voters.

While the Senate is playing green deal or no green deal, the House is caught up in an arcane struggle that gives the term “inside baseball” a bad name. Newly relegated to the minority, House Republicans have been tormenting the Democratic majority with what is known as a motion to recommit.

It is basically one final opportunity for the minority party to amend legislation about to pass on the floor. It has been transformed by both parties over the years as minority leaders have learned to spring politically charged M.T.R.s, as they are known, on the majority at the last minute. Mayor Rahm Emanuel of Chicago, a former member of the House Democratic leadership who cut his political teeth on House races, was one of the early adapters of a weaponized motion to recommit and considered it a form of psychological political warfare.

“Obviously, they are ‘gotcha’ amendments designed to give people political problems,” said Representative Steny H. Hoyer, Democrat of Maryland and the majority leader. “And by the way, that’s what we did. So this is not a new, you know, invention of the Republicans.”

For Democrats, the problem is that Republicans seem to be better at drafting the motions. Now some are passing with the support of nervous new Democratic lawmakers from tough districts who don’t want to be caught on the wrong side of issues such as gun sales, immigration, anti-Semitism or domestic violence. The split has incited an internal party fight and has leaders worried that the more the motions pass, the more they will be considered serious rather than procedural and lead to political problems down the road.