The first House hearing on impeaching the homeland security secretary featured Republicans accusing him of willfully failing to enforce immigration laws and an expert who testified there was no case.
The visit by the speaker and scores of House Republicans comes as the G.O.P. seeks to increase pressure on President Biden and Democrats to agree to severe new border policies.
The majority leader said he would keep the Senate in session to allow time for an elusive immigration compromise, as Democrats criticized the G.O.P.-led House for leaving without helping Ukraine.