Democrats’ Climate Deal Isn’t Done Yet. Here Are the Remaining Hurdles.

“We have a good, balanced piece of legislation. It’s taken me eight months to get here,” Mr. Manchin said. “The process is what it is. You respect the process, and we’ll see what happens.”

In a notice reviewed by The New York Times, Democratic floor staff offered some advance advice for senators and their aides as they looked toward the marathon voting session. “Please be patient, stay hydrated, wear comfortable shoes, bring snacks for your hideaway, a blanket for your lap as it usually gets cold in the chamber at night and anything else to make you comfortable as we hunker down and get to work,” it said.

Democrats need to stay coronavirus-free.

Unlike the House, the Senate does not have proxy voting that enables lawmakers to vote remotely. The even partisan split in the chamber means that, if all Republicans were present, all 50 senators who caucus with Democrats would also have to be present to muster enough votes for the measure, which would still need the tiebreaking vote of Vice President Kamala Harris to pass.

A recent uptick in coronavirus cases in Congress could imperil those plans.

Senator Richard J. Durbin of Illinois, the No. 2 Democrat, remained in quarantine on Monday after testing positive last week, but he was expected to return before the end of the week. One Republican, Senator John Cornyn of Texas, said on Monday that he had tested positive for the coronavirus, but said of a vote on the reconciliation bill, “If it happens, I will be there, consistent with CDC guidelines.”

The House needs to pass the package.

Assuming the legislation clears the Senate, the House will need to return to Washington to approve the measure. While lawmakers remain scattered across the country for a scheduled summer recess, Speaker Nancy Pelosi of California and Democratic leaders have said they will call the chamber back into session — with 24 hours’ notice — to vote on the plan.

With just a few votes to spare in the House, Democrats will have to remain united behind the plan to push it through over Republican opposition. Some progressives have expressed frustration about the scaled-down scope of the package and fossil fuel provisions included at the insistence of Mr. Manchin. But many of them have praised the ambitious climate initiatives as worthy of support.