The top House Republican spent freely to try to block extreme candidates who could imperil the party’s chances of winning the majority or challenge his path to the speakership. Some won anyway.
A handful of Republicans who heeded President Donald J. Trump’s call to march to the Capitol are now vying to return to Washington, this time as lawmakers.
Mr. Majewski, a surprise victor this week in Ohio, has voiced sympathy for QAnon believers and suggested that the F.B.I. drove much of the violence at the Capitol riot.