Mr. Trump has remained defiant, insisting he had done nothing wrong. He was expected to meet Friday at the White House with his personal lawyer, Rudolph W. Giuliani, whose intense public pursuit of the investigations into Mr. Trump’s political rivals provided the kindling that helped fuel the impeachment inquiry.
Over the past two weeks, the president declined to send his lawyers to participate in the hearings or offer a White House defense before the House, breaking with the approach of Nixon and Mr. Clinton. He did not want to lend the proceedings legitimacy and argued he would get a fairer trial in the Senate.
Republican leaders in the upper chamber indicated on Thursday, in the run-up to the vote, that they wanted a speedy trial and would work hand-in-glove with Mr. Trump’s defense team — an announcement that quickly drew a rebuke from Democrats who pointed out that senators take an oath to “do impartial justice” in an impeachment trial.
Asked on Friday if he wanted a short trial, Mr. Trump said, “I’ll do whatever I want.”
He added, “We did nothing wrong, so I’ll do long or short.”
Senator Mitch McConnell, Republican of Kentucky and the majority leader, predicted there was “no chance” 67 senators — the two-thirds majority needed for a conviction — would vote to remove Mr. Trump in an election year.
Unlike during Watergate, when the public came to broadly support removal, or in 1998, when a clear majority opposed it, public polling in recent weeks suggests that Americans are as divided as their elected lawmakers with little signs of change. Some polls show a slight majority of the public supports impeachment and removal, roughly the same fraction who voted against Mr. Trump three years ago.
Still, the echoes of history were hard to miss. The charges against Mr. Trump paralleled some of the articles drawn up against Nixon. And Thursday’s vote fell almost exactly 21 years after the Judiciary panel voted to recommend the impeachment of Mr. Clinton, on charges of perjury, obstruction of justice and abuse of power.