Logistically, impeaching a president or other top government official involves two steps.

A majority of the House must first vote to approve articles of impeachment, which essentially serve as an indictment of the official and sets up a trial in the Senate. Then, two-thirds of the Senate must vote to convict the official to remove him or her from office.

To date, only two presidents have been impeached — Andrew Johnson and Bill Clinton. Both were acquitted in the Senate. According to the Congressional Research Service, of the 15 federal judges, one senator and one cabinet member whom the House has voted to impeach since 1797, the Senate convicted eight federal judges.

For those hoping that Congress might impeach Justice Brett M. Kavanaugh, there is even less precedent for impeaching members of the nation’s highest court than for the presidency. The House has only once voted to impeach a Supreme Court justice — Justice Samuel Chase in 1804 — and he was also acquitted by the Senate.

Mr. Trump, for his part, has cast impeachment proceedings as a political liability for Democrats. In a Friday tweet, he also again wrongly claimed that he is the most popular Republican president in histo ry.