WASHINGTON – 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 “no” votes came from Sen. Richard Burr (R-N.C.), who does not normally buck the White House or leadership. Burr’s office had no immediate comment.

Sen. Susan Collins (R-Maine), a moderate who is one of the Republicans who most frequently sides with Democrats, cast the other “no.”

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 Forest Service land acquisition to the Millennium Challenge Corp.

Independent analyses said that since most of the money would not have been spent anyway, the actual spending reduction was closer to $1 billion. That’s a tiny fraction of the federal budget, but conservative lawmakers in both chambers viewed it as a start in showing Congress’ commitment to reining in spending in a midterm election year, at a time of drastically rising deficits and debt.

“Rescission authority” is a mechanism little used in recent years that allows presidents to submit to Congress a request to cancel spending it has already approved.