On Tuesday, the committee announced 10 new subpoenas that seemed to expand the aperture of the inquiry even further, seeking information from top officials in Mr. Trump’s White House including Stephen Miller, his senior adviser . . . . In its order to Mr. Miller, the committee said that he had helped to spread false claims of voter fraud in the election, and to encourage state legislatures to appoint alternate slates of electors in an effort to invalidate Mr. Biden’s victory.