The Democrats' massive voting rights package — and in turn, the debate over eliminating the filibuster — will be brought to the forefront Tuesday through a procedural vote.

Why it matters: The vote on the For the People Act will be a key indicator of whether Democrats will move forward with their most controversial — but highest priority — legislation, or will be forced to retreat.

• If all 50 Democrats get on board, then the conversation about how to proceed — including calls for abandoning, or at a minimum revising, the filibuster — will ramp up.
• Preserving voting rights is expected to be a flashpoint for the midterm elections — for both parties.
• And many Democrats fear that if they don't eliminate the filibuster to pass their agenda while in control of both chambers of Congress and the White House, their supporters will retaliate at the polls, or by not voting at all.

Driving the news: The view among Democratic leaders and the White House is they can't set up bypassing the filibuster until they get everyone together on a voting rights package.

• All eyes are on Sen. Joe Manchin (R-W.Va.), who, as of now, has not been clear about whether he'll vote to advance the For the People Act for further debate.
• Regardless of how he votes, the motion will fail because it has no shot of getting the 10 Republican votes needed to achieve the 60-vote threshold for major legislation.

But, but, but: Two Democratic senators — Manchin and Kyrsten Sinema of Arizona — have said since January they're not going to get rid of the filibuster.

• And even if Manchin votes to clear this procedural hurdle, it doesn't mean he'll vote in favor of the package, or change the filibuster.
• "There's still a million outs for Joe Manchin, regardless of how he votes" Tuesday, a senior Senate Democratic aide told Axios.
• But a successful procedural vote would kick off the next series of steps in both the voting rights fight and the question of how to deal with the filibuster.

Between the lines: This is a bill Democrats never thought would get 60 votes in the Senate.

• When the For the People Act was introduced in the House, it was largely seen as an overly ambitious messaging bill with no shot of becoming law while President Trump ruled the White House and Sen. Mitch McConnell (R-Ky.) led the Senate.
• But once Joe Biden became president and Democrats took control of both chambers of Congress, the party's progressive wing saw the bill as its chance to make good on a promise to overhaul the nation's election laws and strong-arm more moderate Democrats into eliminating the filibuster.
• The problem with this approach is it's since splintered the party over the decision and puts several Democratic senators — particularly those up for re-election in competitive districts — in an awkward position about how they vote.

The big question: When does Vice President Kamala Harris get more involved?

• The president has made clear this package is a top priority and has charged Harris with getting it over the finish line.
• As of now, she's applied hardly any public pressure on Congress.
• Expect this to change as the midterms approach.

Timing: The current Senate majority leader, Chuck Schumer (D-N.Y.), has said he wants to vote on a voting rights package in August.

• That deadline is closer than it may appear, since the Senate is already breaking for a two-week recess starting next week.