Here's the latest on the impeachment vote.

Threats of impeachment have become a favorite pastime for Republicans, following the example of former President Donald J. Trump, who has urged allies for payback for his own two impeachments during his time in office. The chances of Mr. Mayorkas, let alone Mr. Biden, ever being convicted in the Senate, without some shocking revelation, appear to be virtually zero, and the others appear to be in no serious danger of even being formally passed by the House are accused.

But impeachment, once seen as perhaps the most serious check on corruption and abuse of power developed by the Founders, now appears in danger of becoming a constitutional dead letter, just a weapon in today's bitter, tit-for-tat party political wars. Mr. Trump's two acquittals made clear that a president could be assured of retaining office, no matter how serious his transgressions, as long as his party stood by him and the impeachment effort in search of a major crime is the Biden era written off as just more politics.

“Impeachment has become more of a political and public relations tool than a serious mechanism of executive accountability,” said Jack Goldsmith, a Harvard Law School professor and former top Justice Department official under President George W. Bush. “It is consistent with the decline in standards in Washington's institutions and the ever-increasing weaponization of legal tools to harm political opponents.”

When drafting the Constitution, the framers chose to include an impeachment clause to prevent the despotism from which the Americans had just freed themselves during the Revolution. Initially, they decided that presidents and other officials could be impeached by a majority in the House of Representatives and convicted by a two-thirds majority in the Senate for “treason or bribery.”

George Mason thought this was too restrictive and proposed adding “mismanagement” as a criminal offence, i.e. incompetence. But James Madison objected, finding it too broad and arguing that it would make the president subject to the whims of the Senate. Mason withdrew, but then proposed the phrase “or other high crimes and misdemeanors” as an alternative.

It was elegant, but the framers hadn't precisely defined it. Alexander Hamilton made it clear that the phrase meant transgressions “relate primarily to injuries immediately inflicted on society itself” – in other words, no ancient crimes would be impeachable, but only those that were an insult to the people or the system.

It was meant to be rare and for decades it was. Only 21 times has the House of Representatives voted to impeach a government official, and only eight times has the Senate convicted and removed from office, all judges who otherwise had life terms. The only other Cabinet official targeted for impeachment, William Belknap, the war secretary under President Ulysses S. Grant, accused of corruption, resigned in tears minutes before the House took up his case in 1876, but lawmakers voted to impeach him anyway.

It was so rare that no president was impeached until 1868, when President Andrew Johnson came within one vote of being convicted in the Senate. It was 130 years before another presidential impeachment took place, against Bill Clinton, who was also acquitted, and only 21 years passed between the second presidential impeachment and the third, involving Mr. Trump.

Just over a year passed between the third and fourth, when Trump was impeached for the second time. If the House impeaches Mr. Biden, there will have been three presidential impeachments in five years — more than in the previous 230 years of the republic combined.