Despite years of speculation, Mr. Trump’s impeachment did not, in the end, grow out of the two-year investigation into Russian election meddling by Robert S. Mueller III, the special counsel, or the seemingly endless series of other accusations of corruption and misconduct that have plagued this White House: tax evasion, profiting from the presidency, payoffs to a pornographic film actress and fraudulent activities by his charitable foundation.
Instead, the existential threat to Mr. Trump’s presidency centered around a half-hour phone call in July. On it, he pressured Ukraine’s president to announce investigations into former Vice President Joseph R. Biden Jr. and other Democrats at the same time he was withholding nearly $400 million in vital military assistance for the country and a White House meeting.
Congress learned about the call after an anonymous C.I.A. official lodged a whistle-blower complaint in August — pulling a string that helped unravel an effort by the president and his allies to pressure a foreign government for help in smearing a political rival. Over a period of weeks this fall, a parade of diplomats and other administration officials confirmed and expanded on those revelations.
When Congress sought to investigate, the president ordered his administration to defy its every request, leading to what the House said Wednesday was a violation of the separation of powers and a de facto assertion by Mr. Trump that he was above the law.
United in their opposition, Republicans accused the Democrats, who fought their way back from political oblivion in 2016 to win the House in 2018, of misusing the power voters had invested in them to harangue a president they never viewed as legitimate by manufacturing a case against him. Though they conceded few of them, they insisted the facts against Mr. Trump nonetheless fell woefully short of impeachment.
“When all is said and done, when the history of this impeachment is written, it will be said that my Washington Democrat friends couldn’t bring themselves to work with Donald Trump, so they consoled themselves instead by silencing the will of those who did, the American people,” said Representative Mark Meadows, Republican of North Carolina.
Throughout the inquiry, even as Republicans raged against the process and sought to offer benign explanations for Mr. Trump’s conduct, none disputed the central facts that served as its basis: that he asked Ukraine’s president to “do us a favor” and investigate Mr. Biden, a prospective rival in the 2020 campaign, and other Democrats.