Senate Majority Leader Mitch McConnell (R-Ky.) — having already secured GOP votes for his preferred trial framework — could start the impeachment trial shortly after he receives the articles.

Pelosi and Senate Minority Leader Chuck Schumer (D-N.Y.) had sought to pressure Republicans into accepting new witnesses and evidence in a bid to ensure a fair trial, but McConnell ultimately rebuffed them.

McConnell said Friday that he was "glad" the articles of impeachment were finally being sent to the Senate.

"We've been anxious to get started ... how many weeks has it been now?” McConnell told reporters. "It's been a long wait, I'm glad it's over."

McConnell, who replied "not really" when asked if he'd spoken with Pelosi, didn't specify when he plans to introduce his resolution for the terms of the Senate impeachment trial.

"We have to get the articles first and hopefully then — looks like they're now coming over at long last," he said.

McConnell told Senate Republicans Thursday he was expecting Pelosi to send over the articles of impeachment as soon as Friday, teeing up a Senate trial to possibly start next week.

McConnell also signed onto a Senate GOP resolution to change the chamber’s rules and dismiss Trump’s impeachment if House Democrats didn’t transmit the articles within a certain timeframe, further underscoring he had no intentions of honoring Pelosi’s wishes.

“Yesterday, he showed his true colors and made his intentions to stonewall a fair trial even clearer by signing on to a resolution that would dismiss the charges,” Pelosi wrote in her letter.

The Kentucky Republican wants to use the same process for Trump’s impeachment trial as was used by the Senate during former President Bill Clinton’s 1999 trial. That postpones the issue of witnesses until after the House has presented its case for removing Trump from office, and the response by the president’s legal team.

Pelosi, Schumer and rank-and-file Democrats have complained that McConnell will use the process to block witnesses, thus avoiding the introduction of new evidence that has emerged since the Dec. 18 vote by the House to impeach Trump. Former national security adviser John Bolton, ousted by Trump in early September, has offered to testify if subpoenaed about the Ukraine scandal since that date. Bolton was a key figure in the internal White House debate over Ukraine military aid that led to Trump’s impeachment.

In Maine, Sen. Susan Collins (R-Maine) said she’s been working with a small group of senators to ensure there’s a pathway to calling witnesses, despite the GOP’s plans to defer those decisions until later in the trial. Sen. Mitt Romney (R-Utah) has also said he’d like the opportunity to call witnesses at some point in the trial, including Bolton.

“We should be completely open to calling witnesses,” she said Friday, according to the Bangor Daily News.

Pelosi had been especially tight-lipped about just when she would send over the articles, revealing little to reporters as she walked back to her office Friday, even as the letter was being sent to Democrats at the exact same time.

“Absolutely total cooperation,” Pelosi told reporters Friday when asked about the support she’s received from Democrats for withholding the articles. “We have 1,000 flowers blossoming beautifully in our caucus.”

The speaker for weeks had resisted pressure to transmit the articles, despite McConnell and other Republicans taunting her, saying it was further evidence of the weakness of Democrat’s case against the president. But pressure began to build this week, with several Senate Democrats, and even a smattering of House Democrats, saying publicly that it was time for Pelosi to relent.

Pelosi has yet to give any indication who she will tap as impeachment managers, the House Democrats who will prosecute the case against Trump. House GOP leaders picked 13 Republicans to serve as impeachment managers during Clinton’s trial but several sources close to Pelosi say her team will likely be smaller.

Nadler and House Intelligence Committee Chairman Adam Schiff (D-Calif.) are almost certain to be picked as impeachment managers but the other Democrats Pelosi is considering is subject to speculation.

Under the Senate's procedures, if the House sends its slate of impeachment managers to the Senate on Tuesday, a Senate trial would be triggered the following day and the articles of impeachment would be formally presented to the chamber. Shortly thereafter, Chief Justice John Roberts would be sworn in to preside over the trial and administer an oath of impartiality to the Senate.

During the Clinton trial, the Senate adopted trial procedures the day after lawmakers were sworn in and the trial was recessed for nearly a week, while House impeachment managers and the White House drafted briefs that laid out their formal arguments.

Pelosi’s announcement means that three Senate Democrats who are currently seeking their party’s presidential nomination — Elizabeth Warren of Massachusetts, Bernie Sanders of Vermont, and Amy Klobuchar of Minnesota — will now be able to attend a presidential debate in Iowa on Tuesday night without worrying about the start of the impeachment trial.

But it also means that throughout the rest of the month of January and into early February, that trio — along with Sens. Cory Booker of New Jersey and Michael Bennet of Colorado — will likely be tied down in the Senate participating in the trial.

Kyle Cheney and Burgess Everett contributed to this report.

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