“The highest of high crimes is abuse of power,” said Representative Jerrold Nadler, Democrat of New York and the chairman of the committee. Describing the facts of the case against Mr. Trump as “overwhelming,” he added, “We cannot rely on an election to solve our problems when the president threatens the very integrity of that election.”

Republicans on the panel voiced their indignation about what they said was a refusal by Democrats to accept Mr. Trump’s legitimacy, portraying the bid to impeach him as little more than the climax of a three-year effort to reverse the outcome of Mr. Trump’s 2016 election victory.

They argued that the case against Mr. Trump was overstated and insufficiently proven, and they denounced the impeachment inquiry, saying it was unfair to Mr. Trump and his Republican allies.

“The big lie is that a sham impeachment is O.K., because the threat is so real and so urgent and so great,” said Representative Doug Collins of Georgia, the top Republican on the panel. Mr. Collins accused Democrats of being a “party that has lost all moorings of fairness and good taste.”

“This is as much about political expediency as anything else,” he added.

The rancorous back-and-forth stretched into the night as all 41 members on the notoriously partisan panel had the chance to deliver their opening remarks in one of the most consequential deliberations in more than two decades. The gathering unfolded exactly 21 years to the day after the Judiciary Committee voted to approve articles of impeachment against President Bill Clinton.