How the narrow Senate majority will shape Biden's presidency

Bottom line: When Biden is sworn in Wednesday, we still may not know some of the basic tenets of how the Capitol will function during his first two years. There still is not an organizing resolution laying out the rules that will govern the 50-50 Senate over the next two years. We still have no official word on when there will be an impeachment trial, and the fight over fast-tracking Biden's nominees has already begun.

Big picture: A normal pace isn't coming anytime soon. Sources have repeatedly told CNN that the next days and weeks will test both parties and the institutions they inhabit. Fights over the constitutionality of impeaching an ex-President are already beginning. Slow-walking Biden's nominees is already underway. And besides the daily business of governing, each party is reckoning with its future. Republicans must recalibrate and decide what their party stands for in the wake of Trump. Democrats -- now finally in power -- must decide how hard they want to push the agenda of their base all the while being governed by a President who has always valued compromise.

When does the change happen?

In a matter of hours, the US Senate will change hands. After Biden is sworn in at 12 p.m. ET, three new Democratic US senators will be sworn in at 4:30 p.m., officially cementing a shift in power in the chamber. There is no big vote or ceremonial changing of the guard. Sen. Chuck Schumer of New York will become the majority leader. Sen. Pat Leahy, a Democrat from Vermont, will become the President Pro Tempore.

Biden's nominees face Senate slog

Nominations won't necessarily be easy. Missouri Republican Sen. Josh Hawley made it clear on Tuesday that he would slow walk the nomination of Biden's Homeland Secretary Alejandro Mayorkas, a potential sign that Biden's fight for even his security-related nominations is going to be hard-fought. In his statement, Hawley said his reason was because Mayorkas had not "adequately explained how he will enforce federal law and secure the southern border given President-elect Biden's promise to roll back major enforcement and security measures."

So far, no other senator has come out publicly saying they'll stand in the way of Biden's nominees on other key agencies like Defense, Treasury or State or director of national intelligence. The tone and tenor of those nomination hearings on Thursday made it clear that it's likely those nominations will move more quickly. But we still don't have official word that any of those nominations are moving on Wednesday, either.

On Thursday, the House will vote on a waiver for Lloyd Austin's nomination for defense secretary, a process that will just add a day or two to his potential confirmation. Hawley's move underscores the reality that any member can disrupt -- or at least delay -- Biden's agenda, and with a handful of Republican senators training their eyes on running for President in 2024, expect these moments to come around from time to time.

The organizing resolution

Schumer and current Senate Majority Leader Mitch McConnell met on Tuesday to iron out the organizing resolution for the next Senate. Schumer offered McConnell a resolution that looked almost identical to the one from 2001 between Republican Trent Lott and Democrat Tom Daschle that split committee membership and budgets, established a protocol for how to get things out of committee when they were stuck due to a tie and allowed members of both parties to preside over the chamber.

McConnell wants to cement another change: a promise to keep the legislative filibuster. Practically speaking, the filibuster isn't going anywhere with or without the organizing resolution. With a narrow majority, Schumer would have to have all of his members and Vice President Kamala Harris breaking the tie to "go nuclear." We know from comments by moderates like Sen. Joe Manchin, a Democrat from West Virginia who is opposed to eradicating the filibuster, that Schumer wouldn't have the votes for that.

Still, it's a strategic move on McConnell's part and a way to enshrine minority rights. Putting it in the organizing resolution would also start Schumer out in a difficult spot with his base. It would set a precedent for future organizing resolutions and make it harder for Democrats to do away with the 60-vote threshold on legislation. As with all of these negotiations, remember that staff is still working through this. Just because McConnell and Schumer don't sit down in a room to hammer this out doesn't mean negotiations aren't ongoing.

Impeachment

The timeline for a trial hasn't materialized since the House voted a week ago to impeach Trump for a second time. On Wednesday, Democrats want to make this moment about Joe Biden. Don't expect any announcements. Aides and members we are talking to have made it clear that nothing on the timing of an impeachment trial is expected to be worked out until Schumer and McConnell hammer out their organizing resolution. And Democrats would also like to ensure that at least some of Biden's nominees are confirmed before they lock themselves into a static schedule that comes with the trappings of a trial.

Ultimately, this is still House Speaker Nancy Pelosi's call, but if anyone understands a political moment, it's her. The extent to which members and aides tell me they are in the dark about what comes next is extraordinary for a town where people like to talk. The effort has clearly been made to make this day and week about Biden and not about the impeachment of the last President.

Complicating the timeline for a trial is the fact that Republicans are sending signals that they aren't likely to agree to let Biden fast-track nominees in the morning before a Senate trial begins every day at 12 p.m. Sen. John Cornyn, a Texas Republican and member of leadership, told reporters on Tuesday that dual tracking the day "is not going to be possible."

"It's Nancy Pelosi's choice because once she sends the article of impeachment over, it displaces all other business," Cornyn said. "If she wants to delay the confirmation of President Biden's nominees to Cabinet positions and prevent President Biden from asking for and receiving additional Covid-19 relief, that would be one way to do it, so they have a big decision to make."