The senator's casket will lie in state in the Capitol rotunda overnight, watched by an honor guard. Congressional leaders and Vice President Pence paid tribute in Friday's memorial service.

After criticism, President Trump directed federal flags to fly at half-staff to honor Sen. John McCain until he is buried. The move came after the White House flag was initially at full-staff Monday.

Schumer took issue both with the president's legal team arguing he has the authority to self-pardon and Trump calling special counsel Robert Mueller's probe "unconstitutional."