WASHINGTON (AP) — The House shrugged off a White House veto threat and voted Thursday to repeal a tax that President Barack Obama's health care law imposed on medical equipment makers.

The Republican-led chamber has voted more than 50 times since 2011 to void all or part of Obama's overhaul, usually along party lines. In this case, Republicans were joined by roughly four dozen Democrats from states where medical devices are made to erase the 2.3 percent tax.

The measure's fate is uncertain in the Senate. Foes of the tax would probably have a difficult time mustering the two-thirds majorities Congress needs to override a veto.

Thursday's 280-140 House vote came as lawmakers brace for a Supreme Court decision as soon as next week that could erase a more vital piece of the 2010 law — federal subsidies millions of Americans use to help buy coverage.

The medical device tax, which took effect two years ago, was designed to help pay for the health care overhaul, which has expanded coverage for millions of people. It is imposed on equipment like artificial hearts and X-ray machines, but not items used by individuals, like eye glasses.

Opponents of the repeal effort say taxes the law imposed on many branches of the health care industry were outweighed by added customers the law has created. They also object that opponents would pay the $24 billion, 10-year cost of repeal with bigger federal deficits.

In a letter issuing its veto threat, the White House said repealing the tax "would take away a funding source for financial assistance that is working to improve coverage and affordability" of health care.

Supporters of repeal — including Democrats from states where the devices are made — say the tax drives up companies' expenses and stifles innovation. Rep. Larry Bucshon, R-Ind., called it a "job-killing tax."

The House is expected to take another shot at the health care law next week and vote to eliminate the Independent Payment Advisory Board that the law established to find ways to reduce Medicare spending.

Republicans say that board's proposals would lead to health care rationing. Democrats say the repeal effort is simply another GOP effort to weaken the overhaul law.

Thursday's vote came with Congress more focused on the imminent Supreme Court decision on whether federal health care subsidies have been distributed legally.

A ruling voiding the subsidies would be a major blow to millions of people and to Obama's prized health care overhaul, which relies on the assistance to help make insurance affordable.

House and Senate Republicans briefed rank-and-file GOP lawmakers on Wednesday about their plans should the court annul many of those subsidies. With Republicans running Congress, most want to find a way to avoid being blamed for causing such problems and antagonizing voters.

Conservatives bringing the case say the law's language limits subsidies to people in states that run their own insurance marketplaces — and not to residents of roughly three-dozen states relying on the federal HealthCare.gov website.

The Health and Human Services Department says canceling those subsidies would deprive 6.4 million people of assistance. Many experts say most would drop coverage, which would become unaffordable.

Under the tentative House GOP proposal, the subsidies would continue for a year. Then, states could design their own plans for funneling federal health dollars to residents and drop the health law's consumer protections, such as guaranteeing that family policies cover children until age 26.

In 2017 — when Republicans hope to control the White House — the entire health law would be eliminated.

The Senate GOP plan, which could change, would continue federal aid for people who lost subsidies until after the 2016 elections, said a chief author, Sen. John Barrasso, R-Wyo.

Like the House plan, it would erase the mandates for individual and employer-provided coverage. Democrats say without those requirements, the health law would not function properly because too many people would be uncovered.

It remains unclear whether Republicans would have enough votes to push such plans through Congress. Solid Democratic opposition and a virtually certain Obama veto would await them.