“The first time they brought the freshmen onto the floor for orientation, they said, ‘Spouse?’ ” she said on Tuesday. “I shook my head no. They said, ‘Member?’ I shook my head yes. It was almost as if they couldn’t believe it.”

For some, Tuesday was a day to stake out alliances and make the tough choices that go with becoming a representative of the people.

Representative Mark Walker, a deeply conservative North Carolina Republican and Baptist pastor, said he was under pressure from his new constituents to vote against Mr. Boehner as speaker. Mr. Walker voted for him anyway, despite hundreds of calls asking him to vote for Representative Louie Gohmert, Republican of Texas, a Tea Party favorite.

“My position was that it’s not enough to be just conservative — you have to have the skills to be a leader,” Mr. Walker said as he waited in the speaker’s photo line. As he spoke, his daughter called for him; it was their turn to step into the room with the cameras. “Dad!” she said. Mr. Walker scurried off.

With Republicans accounting for roughly two-thirds of the new House members sworn in on Tuesday, the party now has its largest House majority in decades. In the Senate, where the freshman class of 13 includes just one Democrat, the newcomers can take direct credit for putting their party in the majority, and giving Senator Mitch McConnell, Republican of Kentucky, the majority leader’s job.

There, the new members were a bit less obvious. Seven are not only freshmen, but also graduates — of the House.

Among them is Senator James Lankford, Republican of Oklahoma, who was elected to the House in 2010. When he got dressed Tuesday morning to be sworn in, Mr. Lankford put on his navy blue suit, but left off an item that had been an essential part of his wardrobe for four years: the lapel pin that identified him as a member of the House.