Limits of a Democratic majority highlighted as key votes hang in the balance

With key votes all teetering or stalled in the 50-50 Senate, here is a quick primer on where things stand as of Wednesday.

Bottom line: The diverse Democratic caucus that includes moderates like Sen. Joe Manchin of West Virginia, whose constant refusal to gut the filibuster underscores how limited Majority Leader Chuck Schumer's power really is.

Infrastructure

It's going to be a long few months as Democrats grapple with whether they can even pass Biden's top priority infrastructure.

There is an assumption that if Democrats can't strike a deal with Republicans on infrastructure, they'll simply turn to reconciliation and move swiftly.

But, there is no guarantee that process works. (*See above on Manchin. He told CNN's Manu Raju on Tuesday he sees no need for reconciliation at this point. And a handful of other senators say they want to see the process play out. )

Schumer announced Tuesday that he would begin working on Biden's infrastructure plan in July, but convincing Democrats to turn the page on bipartisanship will also be a challenge.

Negotiators from both parties still disagree on the scope, the price tag, the options to pay for it and how much to focus the bill on green energy production.

Democratic Sen. Jon Tester of Montana says, "I am not there yet" on moving on from bipartisanship.

"We will see," he said. "I think there are still conversations that need to be had. I would like to have something done by the time we get out of here in August. I would like to have a commitment for a package then," he said.

Pushed on if he'd really let it go on that long, "I'm not the leader so I can say s*** like that."

What about this bipartisan hill group? Yes, a bipartisan group of senators has been working for months on finding a way forward on infrastructure. But, so far, the ideas they have floated to pay for infrastructure are not likely to be accepted by many Dems.

Their ideas:

Indexing the price of gas to inflationTapping unused state and local funding from the Covid relief billInstituting fees for electric cars who use the country's roads and bridges

They might work for moderates, but remember, you have to sell this to a broader caucus if it is going to become law.

Many of these same players were responsible for shaking loose the eventual Covid relief deal that passed in December and was signed by former President Donald Trump. The group definitely could play a role, but keep your eye on what is happening now between the White House and Senate Republicans.

Voting rights

Democratic lawmakers are slated to meet Wednesday behind closed doors and will discuss the For the People's Act or S1, which the GOP is calling a power grab.

The bill is also stalled as Manchin is withholding his support.

Sources tell CNN Democratic voting rights lawyer Marc Elias is expected to speak to the caucus Wednesday about ways to move forward on the sweeping ethics and voting rights reform bill.

Last time they met, sources described the discussion as 'frank' with several members raising concerns about passing the bill as it was written.

The filibuster

This fundamental disagreement is emblematic of a series of obstacles Democrats are facing.

Even if Democratic leaders could convince a skeptical Manchin to sign on, and he's made clear he won't, Democrats still do not have the 10 Republican votes they need.

That brings us back to the filibuster, and Manchin (and others) won't vote to abolish it even on something like voting rights. Manchin has shown no willingness or interest in getting rid of the filibuster even on voting rights.

"There is more conversation now on the filibuster," Sen. Chris Murphy, a Democrat from Connecticut said. "But we still have to make the case to some of our members that the filibuster is an obstacle to bipartisan compromise."

Yes, Democrats have reconciliation for some issues, but only those which have a direct impact on the budget. For everything else, bipartisanship is the only path forward.

Police reform

This is why police reform talks are so important: The ongoing policing negotiation is a blueprint for how Biden might be able to tackle major, social issues. Those talks, which have seen their own ups and downs, have been fraught at times, but sustained, built on years-worth of relationships between members who trust one another.

Whatever legislation they come up with will have bipartisan buy in and won't require overhauling or rewriting Senate rules to pass it. It's why these talks are bigger than one issue, they prove that Congress can do this hard work and Biden's legacy may be bigger than just what his Democratic caucus can do on its own.

China

A major test for this kind of effort is happening right now on the Senate floor. The innovation and Competitiveness Act, which would shore up the US' ability to compete with China on a global stage was pulled together by multiple committees.

It's still unclear whether the bill will have the backing of many Republicans, but the process has included amendment votes, months of talks and committee mark ups. It's the textbook case of how you are supposed to do things in the US Senate.

The January 6 commission

The effort to establish a January 6th Commission is expected to fail in the Senate on Thursday.

Only two Republican senators have formally said they will back the bill and a number of members have expressed concerns or asked for changes that we have seen no evidence will actually be negotiated.

And even as Manchin and Republican Sen. Susan Collins of Maine are having informal conversations about how the commission bill could earn her support, one aide noted it's still a "heavy lift."

One programming note: The House is out for two and a half more weeks, and after Thursday night's votes, the Senate will be in recess for its week-long Memorial Day recess.