A memo written by Democratic presidential candidate Joe Biden when he was a senator in 1999 has emerged, wherein Biden informed his caucus that "the Senate need not hold a 'full blown' trial" in the upper chamber against former President Bill Clinton.

The document was brought up on the Senate floor Thursday night during the impeachment trial of President Donald Trump, where the president's lead attorney referred to its contents as "The Biden Doctrine."

What are the details?

In the four-page memo obtained by Politico, Biden argued "the Senate need not hold a 'full blown' trial" and presented prior impeachment cases as evidence that "in fact, the Senate need not hold a trial even though the House wishes to present evidence and hold a full trial."

Biden further argued in 1999 that "in a number of previous impeachment trials, the Senate has reached the judgment that its constitutional role as sole trier of impeachment does not require it to take new evidence or hear live witness testimony."

"The public has ability to understand whether it, and its system of government, have been gravely harmed," then-Sen. Biden argued in making his case that the voice of the people should be heard. "Where it (the public) expresses overwhelmingly the view that the President should not be removed from office and expresses this view not in a single poll but repeatedly over the course of a year, this is a constitutionally significant statement."

Politico noted that "Biden's comments from 1999 are at odds with current Democratic talking points that additional witnesses must be called to get to the bottom of Trump's actions in the Ukraine saga."

Report noticed on Senate floor

The Politico report was published at 8:36 p.m. EST on Thursday night, while the Senate trial against President Trump was ongoing and senators were asking questions of House impeachment managers and the president's legal team. News of the memo's contents swiftly made it to the Senate floor.

President Trump's lead counsel, Jay Sekulow, read from Biden's 1999 memo, before declaring to the Senate, "That was 'The Biden Doctrine' of impeachment proceedings."

Sekulow pointed out, "Some members in this chamber agreed with that. Some members that serve as managers also agreed with that," referring to Democratic senators and representatives now seeking to remove President Trump from office.

He noted that "now the rules are different."