White House budget director Mick Mulvaney said the White House would back Senate Republicans if they decide to do away with the 60-vote threshold to end debate on policy bills in order to reopen the government.

However, Mulvaney emphasized the more palatable option is for Senate Democrats to get on board with a continuing resolution to reopen the government and then deal with larger issues after that.

“We cannot open the government without Senate Democrat support. We don't have that, which is why we are where we are and one way around it would be to change the 50 votes,” he said on CNN's "State of the Union." “Another way would be some of those Democrats who say they want to work in a bipartisan fashion, they work with Republicans, but don't. Where are those Democrats that say one thing back home and do another in Washington?”

President Trump urged Senate Republicans to go nuclear, the term for ending the 60-vote threshold to end debate and instead instituting a simple majority vote threshold to end debate, in a tweet Sunday morning. He’s often called on Senate Republicans to go nuclear in order to pass his agenda items, such as repealing the Affordable Care Act.

Three Republicans voted against the continuing resolution to keep the government open for four weeks that failed in the Senate on Friday night. Republicans can only afford two no votes on any majority rules vote — and while Arizona Sen. John McCain is at home fighting cancer, Republicans can only afford one defection.

However, five Democrats jumped across party lines to vote to keep the government open on Friday. Mulvaney said that’s proof the bill has bipartisan support and other Senate Democrats are the ones keeping the government from opening back up.

“This is the type of funding bill that has passed for the last decade. It's a bill that has a funding component for the government and it's a bill that has things that members of both parties say that they like,” he said.

“It's a bill that has the extension for the Children's Health Insurance Program, the delay to the various Obamacare taxes including the Cadillac tax that the Democrats want delayed. … It is a bipartisan bill the Democrats are opposing even though they don’t oppose what is in it.”