After Early Primary Victories, Republicans in Congress Fall in Line Behind Trump

Representative Marjorie Taylor Greene, the Georgia Republican and die-hard ally of former President Donald J. Trump, was exasperated with her colleagues as she left the House floor last Thursday evening.

“I don’t know if it’s sunk in this place around here,” Ms. Greene vented as she headed for the elevators and then for Manchester, N.H., where she was stumping for the former president. “I’ve been telling everyone that President Trump is the leader of the Republican Party; he’s going to be our presidential nominee. It’s time for all Republicans to get behind his policies.”

If it hadn’t sunk in yet, it has now.

After Mr. Trump won the New Hampshire primary by 11 percentage points on Tuesday night following his steamrolling victory in the Iowa caucuses, the small segment of Republicans in Congress who had tried to distance themselves from him, ignore him, cast doubt on his staying power or condemn him have begun swiftly falling into line behind him. And this time, it is happening even faster than it did in 2016, when Mr. Trump first subsumed his party.

In the Senate, at least 29 Republicans — more than half the conference — have now endorsed Mr. Trump, compared with zero for the lone Republican challenger still standing, former Gov. Nikki Haley of South Carolina, who vowed on Tuesday night to carry on with her campaign despite outlining no clear path to victory.