A generational divide, seen in newer lawmakers’ impatience with bipartisanship and for colleagues who don’t understand new media, has emerged as one of the deepest rifts within the party.

Dozens of House Democrats sent a letter to Schumer on Friday to express their “strong opposition” to his plan to back the Republican measure

WASHINGTON—The Senate headed toward a vote Friday advancing a Republican measure to fund the government through September, as heartsick Democrats implored Senate Minority Leader Chuck Schumer (D., N.Y.