It’s official: The federal government has entered yet another partial shutdown. 

The Senate reopened at 12:01 a.m. Friday after recessing just before 11 p.m. Thursday, as Sen. Rand Paul continued his objections to moving up the timetable for a procedural vote on legislation that would extend government funding past the midnight deadline. That vote is currently set for 1 a.m.

The White House gave federal agencies the green light to begin shutdown preparations earlier Thursday evening, as the massive $320 billion budget package hit procedural snags courtesy of Paul.

Earlier, the Kentucky Republican said he was prepared to delay a final vote until the wee hours of the morning if Senate leaders would not allow a vote on his amendment to restore the spending caps that would be increased in the underlying bill. “If they want to stay up until 3 in the morning, I’m happy to do it,” he told Fox News.

In an exchange on the Senate floor, Paul’s home state colleague and Majority Leader Mitch McConnell, as well as Minority Leader Charles E. Schumer, had asked Paul to agree to a 6 p.m. vote on a budgetary point of order in lieu of an amendment debate. Paul objected, insisting that there has been plenty of time Thursday to take up amendments.

Watch: Rand Paul Objects to Expedited Vote on Budget Package

Schumer said allowing a vote on Paul’s amendment would open the floodgates for other senators to demand votes on their own amendments.

House Speaker Paul D. Ryan said earlier Thursday he expected the package would pass both chambers of Congress before government funding runs out, despite objections from some Democrats that the budget deal does not include a legislative solution for undocumented “Dreamers” and frustration from conservatives that the agreement will further increase the national debt.

The measure would keep the government operating through March 23, giving the appropriations committees time to rewrite all 12 fiscal 2018 spending bills to the higher spending levels. The Senate’s floor procedures are complicating the timing.

“I think we will get this done. I feel good about it,” Ryan said Thursday morning on the Hugh Hewitt radio show.

The Senate plan, assuming the chamber achieves cloture during the 1 a.m. vote, is to substitute the package into a funding bill passed by the House on Tuesday. Then the amended legislation would go back to the House for a final vote, sometime early Friday morning likely before the federal workday begins.

The last partial shutdown occurred just two weeks ago, when the Senate could not pass a three-week stopgap until the afternoon of Monday, Jan. 22; the shutdown began after midnight Friday, Jan. 19.

Watch: Highlights from the Last Shutdown Floor Debate

Last stand for House Democrats

That was hours before objections from Paul became known, and before House Democratic leaders said they’d whip against passage in that chamber.

House Minority Leader Nancy Pelosi said she and many House Democrats will vote against the package. She spoke on the House floor for more than eight hours Wednesday to press the case for Dreamers and is seeking a promise from Ryan that he will hold an open amendment process on a DACA bill.

Pelosi did not go as far as saying House Democrats would be able to stop the legislation from becoming law.

“It’s a good bill. It’s unfortunate it’s taking place in an insulting way,” the California Democrat said at a news conference.

Pelosi called on Ryan to “man up and decide that we in the House can have what Mitch McConnell guaranteed in the Senate,” referring to the Senate majority leader’s commitment to a full debate on immigration legislation. She explained that she wants Ryan to commit to what’s called a “queen of the hill” process, which would allow for votes on numerous measures with the one that gets the most support over a simple majority prevailing.

Ryan said during a subsequent news conference that he intends to bring up DACA legislation, but did not commit to any amendment process.

“I know that there is a real commitment to solving the DACA challenge in both political parties. That’s a commitment that I share. To anyone who doubts my intention to solve this problem and bring up a DACA and immigration bill. Do not,” Ryan said. “We will bring a solution to the floor. One that the president will sign.”

The continuing resolution that must pass Congress to restore the government funding would be the fifth since fiscal 2018 began in October.

Trump has already indicated he will sign the legislation into law, tweeting on Wednesday that “Republicans and Democrats must support our troops and support this Bill!”

Watch: Congress, Trump Spar Over Shutdown, Then Another Memo

House Democrats remain somewhat divided on their stance.

“My sense is that at this moment people don’t want to shut the government down, they want to fund programs, we’re a nation at war, we can’t keep putzing around,” Ohio Rep. Marcy Kaptur said prior to the shutdown. “But I don’t believe at this point our leader has gotten any assurance from Mr. Ryan that a bill to solve the Dreamers and DACA in general would be brought up and that it would pass. I can’t figure out why they won’t bring it up?”

With potentially dozens of Republicans expected to vote against the deal due to its spending increases, mass Democratic defections could endanger the package on the House floor, with no Plan B at the moment for keeping the government operating.

Domestic spending, tax changes

The spending deal, announced on Wednesday, would increase discretionary spending for defense by $80 billion and nondefense by $63 billion for the current fiscal year and by $85 billion for defense and $68 billion for nondefense in fiscal 2019. Only about $100 billion of that spending is offset. Those offsets include selling off some of the Strategic Petroleum Reserve, reducing surplus funds at Federal Reserve Banks and extending visa waiver program immigration fees from 2020 to 2027.

Among the spending increases: $6 billion to address opioid addiction and mental health, $2 billion to the National Institutes of Health and $4 billion to help the Veterans Administration Department address its backlog. There’s $20 billion in infrastructure investment and provisions that would help cotton and dairy farmers.

The deal would also benefit at least two colleges in McConnell’s home state of Kentucky, by making changes in the new tax law  pushed by Republicans late last year. The tax section includes a one-year extension of tax breaks that expired at the end of fiscal 2016 on a myriad of issues, ranging from higher education tuition deductions to mortgage debt forgiveness and payments to Puerto Rican rum producers.

The Congressional Budget Office estimates the net budgetary impact of the bipartisan budget deal would be about $320 billion over 10 years, including the combined effect of discretionary spending cap increases, tax and health care provisions, supplemental disaster aid and a variety of user fee extensions and other offsets.

Some of the “pay-fors” were running into objections as well. Senate Banking Chairman Michael D. Crapo said he wanted to remove an offset that would tap Federal Reserve surplus funds by lowering the required balance held by reserve banks from $10 billion to $7.5 billion.

The legislative package also would suspend the debt limit through March 1, 2019, and includes $89.3 billion in disaster aid to assist states and territories damaged by severe hurricanes and wildfires.

Ryan told reporters on Capitol Hill that the hurricane aid is “one-time spending” that is necessary to help disaster victims, while other increases in domestic spending such as science research and addressing the opioid crisis are things “that we all agree on.”

Lindsey McPherson, Doug Sword, Joe Williams and Niels Lesniewski contributed to this report.