New evidence, and now, a new venue.

The two articles of impeachment will be transmitted to the US Senate on Wednesday evening, launching what senators have been anxiously watching, with mixed levels of trepidation and interest, for weeks. Senators in both parties currently sit in a sort of strange middle ground between everyone knowing how it's all going to end and having genuinely no idea what's going to happen between now and then.

Bottom line: The final stage of President Donald Trump's impeachment process is here. The President will, according to Democrats and Republicans alike, be acquitted. But as the new and explosive documents released by House Democrats on Tuesday made clear, what happens between now, and acquittal is completely unknown -- and bound to be packed with surprises that could reshape the Senate trial.

What to watch today

  • House Speaker Nancy Pelosi announces the House impeachment managers at a news conference at 10 a.m.
  • House vote series that will include the impeachment manager resolutions, between 12:30p.m.-1:30 p.m.
  • Pelosi holds engrossment ceremony, then managers begin procession to the Senate to present the articles to the Secretary of the Senate in the 5 p.m. ET hour.

What the Parnas docs mean in the Senate

The reality is at this point, it's unclear. Republican senators haven't said a word and most will likely dodge the question Wednesday related to a new batch of documents from indicted Rudy Giuliani associate Lev Parnas. But there's no question that it adds fuel to the pressure fire Democrats have been hoping to build and fan in the past few weeks. As the House committee chairs said Tuesday upon release of the documents: "There cannot be a full and fair trial in the Senate without the documents that President Trump is refusing to provide to Congress."

And yet: The Senate was done voting for the day by the time the Parnas documents were released so senators were sparse, but I did run into one Democrat who made a point that shouldn't be overlooked in the weeks ahead:

"I look at these and think nobody in their right mind could vote against more documents and witnesses. It's not voting to remove the guy -- it's documents and witnesses! This is literally crazy, the least we can do is talk to more people," the senator told me.

He paused. Then finished: "And then I remember the last three years and think, well yeah, it's entirely possible, if not probable, this doesn't move the needle an inch."

Flagging this: It's a safe bet the Parnas documents won't be the last piece of new evidence or disclosures that throw a wrinkle into the forthcoming trial. In fact, a source tells me a Government Accountability Office report, requested by Democratic Sen. Chris Van Hollen of Maryland, on whether the White House broke the law in withholding the Ukraine aid is coming on Thursday.

Threading the needle

Senate Majority Leader Mitch McConnell said this Tuesday: "I announced that all 53 of us in our conference had agreed on an initial resolution to go forward. And that remains the case."

That statement briefly tipped that behind the scenes, McConnell is still very much in the midst of a high-wire management act. He has a president that changes his mind about what he wants to see -- or demand -- in a Senate trial seemingly daily, people with knowledge of their conversations told CNN. He has politically vulnerable members to stay in touch with and keep the pulse of. He has moderates who have specific demands and constituencies. He has the president's most stalwart allies who are pushing for a very different trial that McConnell wants.

The point here: Just because all 53 Senate Republicans agreed to the topline concept of the initial rules resolution for the Senate trial doesn't mean it's been smooth sailing since. McConnell, according to senators and GOP aides, has still been very engaged on smoothing out language and concerns to make that unanimous support a reality on the floor. There's a reason the rules resolution hasn't been released yet. It's not done.

For example: In a private, 30-minute meeting on Tuesday, Republican Sen. Ted Cruz of Texas walked McConnell through his idea of "reciprocal" witnesses in the trial, according to three sources familiar with the meeting. Cruz's pitch: if Democrats want to subpoena witnesses, say former National Security Adviser John Bolton, then Republicans should get to subpoena, say, Hunter Biden.

The idea came up during a meeting between McConnell and Cruz, Sens. Mike Lee of Utah, John Cornyn of Texas and Lindsey Graham of South Carolina (the meeting was first reported by POLITICO.) Those four have served as McConnell's quiet and informal point men on the process up to this point. Their perspectives matter a great deal.

For example, part two: At the same time, McConnell is actively considering adding new language to the initial resolution dealing with witnesses that has been pushed hard by Republican Sens. Susan Collins of Maine (in particular) and Lisa Murkowski of Alaska, according to a GOP senator familiar with the talks. While talks are ongoing, the topline is it would provide for a protected vote on the sense of the Senate that more information -- witnesses and documents -- and would occur after the first two stages of the trial, the senator said. Again, this isn't final and things are fluid, but it underscores that McConnell is still working through his conference on how to structure the trial.

What it all means: There is often this assumption that McConnell's members just immediately get behind whatever his preferred route is, follow in lockstep and don't ask questions -- something McConnell essentially puts in place through his own counsel. This misses what has made McConnell so effective inside his conference. Yes, the end game often appears that way, but he's always working behind the scenes with his senators to balance their equities and try and find a path to keep everyone unified. It doesn't just happen. And what's occurring now, very quietly, behind the scenes, underscores that when it comes to this trial, it is very much a both fluid and ongoing process.

To make this clear: McConnell has said privately, sources say, that witnesses are a bad idea in his view. He's alluded to this publicly as well. But he's never closed the option for them, and there is nothing he can do in this trial to stop votes to subpoena Democratic witnesses, or even those preferred by the President. In the end, if past is precedent, he'll go where his conference is on this issue. How does it end up? He doesn't know. Nobody does. But everything he's been doing behind the scenes is an effort to try and secure his preferred end game. It is, to a degree, what he's always done.

With that in mind: McConnell's friend here is time. Think about the three-week delay on sending the articles to the Senate. Put aside the public rhetorical broadsides directed at Democrats and look at what happened behind the scenes. He kept his conference together and used the delay to lock in general, unified support for his preferred first stage of the trial.

Now think about how that trial is structured initially. At least two weeks of opening arguments and questions from senators. That's more time for McConnell -- time bolstered by senators stuck on the floor, without electronics, unable to speak, for hours on end each day. The kind of thing that, in the words of one Republican senator, "will drive us all mad."

That, McConnell has told associates, is likely to work to his advantage as he looks to secure a quick conclusion to the trial. It's time to bring his senators with him toward that end game. It's a scenario where his there is a good chance that by the end of those first two stages, his members are simply ready to vote and move on. He'll use that to his advantage. It's what he has always done. The question is whether he can convince 50 of his GOP colleagues to go with him.

Always remember: McConnell's driving force is maintaining his Senate majority and keeping his conference together. The different views inside his conference make that a particularly complicated balancing act in this trial. But he's playing for an end game that protects his vulnerable members, yet pacifies the President's closest allies (and to some degree, the President himself).