Sen. Richard Burr (R-N.C.) (J. Scott Applewhite/AP)

The Senate on Wednesday rejected billions in spending cuts proposed by the Trump administration as two Republicans joined all Democrats in voting no.

The 48-50 vote rebuffed a White House plan to claw back some $15 billion in spending previously approved by Congress — a show of fiscal responsibility that was encouraged by conservative lawmakers outraged over a $1.3 trillion spending bill in March.

The House had approved the so-called rescissions package earlier this month. But passage had never been assured in the Senate, where a number of Republicans had been cool to the idea from the start.

Nevertheless, Wednesday’s outcome was startling because one of the opposing votes came from Sen. Richard Burr (R-N.C.), who does not normally buck the White House or GOP leadership. Sen. Susan Collins (R-Maine), a moderate and one of the Republicans who most frequently side with Democrats, cast the other GOP vote against the cuts.

Burr’s office said the senator was concerned about $16 million in cuts targeting Land and Water Conservation Fund projects under the U.S. Forest Service. The Land and Water Conservation Fund is set to expire in September, and earlier Wednesday Burr led a news conference to call for its extension. The fund uses royalties paid by energy companies that drill on the Outer Continental Shelf to protect natural resources. Burr had not been guaranteed a vote on an amendment to protect the LWCF funding, his office said.

Collins had expressed concerns about cuts to the Children’s Health Insurance Program.

In a statement, White House budget director Mick Mulvaney decried the Senate vote.

“It is disappointing that the Senate chose to reject this common-sense plan,” Mulvaney said, “and the American people should be asking their representatives in Washington one simple question: If they cannot pass good-government legislation to recapture unnecessary funds, how can we ever expect them to address Washington’s staggering debt and deficit problem? “

The cuts in the rescissions package included $7 billion from the Children’s Health Insurance Program, mostly from an expired account that can no longer be used; $5 billion from Energy Department programs, including a little-used loan program for advanced technology vehicle manufacturing; and smaller amounts from a variety of other programs ranging from the Department of Commerce Economic Development Administration to the Millennium Challenge Corp foreign aid agency.

Democrats had accused Republicans and the Trump administration of targeting important programs with the rescission cuts, but Republicans countered that most of the money was sitting unspent, in some cases in expired accounts that couldn’t be tapped.

Independent analyses said that since most of the money would not have been spent anyway, the actual spending reduction in the package was closer to $1 billion. That’s a tiny fraction of the federal budget. But in a midterm election year conservative lawmakers saw the rescissions package as a way to show Congress’ commitment to reining in spending at a time of drastically rising deficits and debt.

“I thought we all campaigned on cutting wasteful spending,” said Sen. Mike Lee (R-Utah), who championed the rescission effort in the Senate. “I thought our party was about lowering federal deficits by lowering federal spending. It saddens me to see people who campaigned on lower spending break their promise and vote with Democrats against President Trump.”

“Rescission authority” is a mechanism little used in recent years that allows presidents to submit to Congress a request to cancel spending that lawmakers have already approved. It’s related to the line-item veto, which Trump asked Congress to give him when he reluctantly signed the giant spending bill in March. However, the U.S. Supreme Court has ruled the line-item veto unconstitutional.

The White House had outlined plans to follow up the rescissions package rejected Wednesday with others making additional cuts, but that may no longer be realistic.

“The Trump-GOP rescissions bill was a disastrous attempt to play election year politics by eliminating funding for children’s health insurance and slashing investments that create jobs and strengthen communities,” said Rep. Nita M. Lowey (D-N.Y.), top Democrat on the House Appropriations Committee. “The Senate was right to reject this attack on American children and families.”