Only a handful of Democrats and none of the party’s top leaders attended the ceremony, an outpouring of praise and mourning for the right-wing activist, who was assassinated last week.

Judge Tanya S. Chutkan said her hands were “tied” with regard to the migrants, even though they held protective orders, in another victory for President Trump’s deportation campaign.

The president and the first lady will be hosted by King Charles III and Queen Camilla at Windsor Castle. Mr. Trump will also travel to the prime minister’s country residence, Chequers.