“The Democrats, whose votes we need in the Senate, will probably vote against Border Security and the Wall even though they know it is DESPERATELY NEEDED,” Trump said in a Friday morning Twitter post. “If the Dems vote no, there will be a shutdown that will last for a very long time. People don’t want Open Borders and Crime!”

The president’s comments sought to preemptively shift blame to the minority party if a funding lapse occurs at midnight, even though Trump has said he’d be proud to shut down the government. The president on Thursday scuttled an apparent deal to fund the government into February when he suddenly said he’d reject it.

House Republicans sought to meet Trump’s demands, adding $5 billion for border wall construction to the Senate’s version of a stopgap spending measure.

But senators from both parties have indicated that the modified legislation won’t pass when the chamber returns for another vote on Friday, leaving lawmakers on both sides of Capitol Hill back where they started with a midnight deadline looming.

White House Press Secretary Sarah Sanders told reporters Friday that the president supports a plan first circulated by Republican Senator Steve Daines to lower the chamber’s effective 60-vote threshold for major legislation. Doing so would allow its 51 Republicans pass the bill with a simple majority, removing Democrats’ ability to block it.

The brinkmanship between Congress and the White House was part of a chaotic week in Washington, with Trump’s last minute rejection of the stopgap spending plan, his sudden announcement of a U.S. withdrawal from Syria and the surprise resignation of Defense Secretary Jim Mattis.

Markets were whipsawed by the turmoil in Washington. Shares turned sharply lower Thursday after Trump hardened his demands with the the Nasdaq Composite index slumping to the brink of a bear market and the S&P 500 closing at a 15-month low.

Trump’s Base

Trump’s insistence on the wall funding after his aides indicated earlier in the week that he’d accept a temporary spending bill without it was a bow to his voting base. After the Senate easily passed the measure without any money for the wall, conservative pundits, voters and lawmakers erupted.

“He sees he is standing with the American people and Congress is standing with him,” said House Freedom Caucus Chairman Mark Meadows, a North Caroline Republican who urged the president to veto any spending legislation that doesn’t include wall funding.

Senate Democratic leader Chuck Schumer of New York said Trump was “plunging the country into chaos.” He called the decision House GOP leaders to add the wall money a “cynical” political ploy.

Normally, when the House and Senate differ on legislation a conference committee can convene to work out differences. With both sides so dug in on the issue of the wall, ideas for a compromise were scarce.

Kentucky Republican Representative Hal Rogers expressed optimism that Congress would find a way out to keep the government open. “If there’s some middle ground here we’ll try to find it,” Rogers said. “There’s always a chance.”

Pessimistic

But Mike Simpson, an Idaho Republican, said the House won’t accept another version from the Senate without the wall money and that means a shutdown is likely.

Trump won’t travel as planned to his Florida resort for the holidays if there’s a shutdown, spokeswoman Sarah Huckabee Sanders said at the White House.

Trump’s wall plan had deep support among Republican voters, but a majority of the wider electorate opposes him, polls show. The president hammered on the border security issue in the weeks leading up to the November midterm elections, in which Republicans lost a net 40 seats in the House, turning over control to Democrats.

Senate to Meet

The Senate is scheduled to convene at noon Friday. Senate Majority Leader Mitch McConnell of Kentucky is almost certain to advance the same measure, without wall money, that the GOP-controlled chamber easily passed by voice vote Wednesday.

The Senate bill would keep the government agencies open through Feb. 8, and is intended to delay a fight over the wall funds until then.

House Speaker Paul Ryan of Wisconsin and his leadership team had begun the day Thursday planning to hold floor votes on the Senate’s spending package. But Ryan came under heavy criticism from conservatives during a private party meeting and then was called out to speak to Trump on the phone, several lawmakers said.

Ryan—who has been busy giving a series of farewell speeches in recent weeks as he plans to leave office—canceled a scheduled press conference before he and other House GOP leaders were summoned to the White House.

Trump during the meeting said he would not sign the Senate-passed measure, prompting Republicans to rewrite the bill.

The economic effects of a shutdown over the Christmas and New Year holidays may be limited. Seventy-five percent of the $1.2 trillion federal discretionary budget has been funded through the Sept. 30 end of the fiscal year.

Without a spending bill, about 400,000 “essential” employees like border guards and airport screeners would continue to work without pay while about 350,000 other workers would be sent home. Federal grants, loans and purchases would also cease for the areas of the government affected.

As House Republicans settled on their plan to fight for Trump’s wall, some Republican senators expressed frustration over the dispute and Trump’s shifting signals over whether or not he would sign legislation to keep the government open.

Asked if he believes Trump might still sign a stopgap bill without wall funds, Republican Senator Bob Corker of Tennessee said, “Who knows?”

“Does the person sitting beside him at the White House know?” Corker said. “Who would know?”