The GOP is redoubling its efforts to eliminate ObamaCare’s individual mandate, a step that would be yet another blow to the health-care law.

They are doing so even as key Senate Republicans seek a bipartisan deal that could strengthen the law by extending critical payments to insurers that help low-income people afford their copays and deductibles.

{mosads}The requirement that everyone buy insurance or pay a penalty is a bedrock principle of the health law, and following the failure of the Senate to repeal ObamaCare in its entirety, the mandate has become a fresh target for conservatives.

The White House this week said the bipartisan bill negotiated between Sens. Lamar Alexander (R-Tenn.) and Patty Murray (D-Wash.) must repeal the individual mandate before President Trump would support it.

“If we really want to reduce prices, then we need to begin repealing the mandates and repealing the taxes and then we could have a deal,” White House director of legislative affairs Marc Short said on CNN Thursday.  

“We need a lot more than what’s in the bill right now,” Short said.

The deal would currently fund two years of cost-sharing reduction payments, which Trump has called a “bailout” for insurers. It would also broaden waivers to let states change certain ObamaCare requirements.

Some GOP senators are also trying to weaken or completely remove the mandate, to make it more likely to win favor in the House. For example, Sen. Ron Johnson (R-Wis.) is pushing for the bill to waive the penalty for not having insurance in 2017.

Supporters of ObamaCare are worried that the administration could ease up on enforcement of the mandate, which could undermine the stability of the markets under the law if healthy people decided to drop coverage.

But getting rid of the individual mandate is not so simple.

The penalty for not having insurance is written into law and enforced by the IRS, which means that only Congress has the power to repeal it. The Senate attempted to do just that with legislation that would have repealed most of ObamaCare with only 51 votes.

Those efforts failed, so any additional legislation that targets the mandate will need 60 votes to pass. Republicans only have a 52-seat majority.

The administration could try to pressure the IRS into not enforcing the mandate, but the agency is largely insulated from political pressure, said Jason Levitis, a policy expert at Yale Law School and former senior official in the Treasury Department under former President Obama.

“The IRS’s job is to enforce the tax code and the mandate is part of it,” Levitis said. “The mandate is still the law of the land.”

Trump could also try to issue executive orders to weaken enforcement or create more exemptions to the mandate. Yet experts say the president’s ability to do so is limited.

Timothy Jost, an Emeritus Professor at the Washington and Lee University School of Law, said hundreds of thousands of people already get exemptions from the mandate. There isn’t much room to lawfully expand the exemptions, he said.

Republicans want to repeal the mandate because they say it’s an unaffordable burden on working class Americans. One of the main GOP attacks on ObamaCare is that it’s resulted in unaffordable premium increases, and the mandate isn’t helping.

Experts said it is perception, sometimes more than action, which can influence insurers and lead to premium spikes. If the public thinks the mandate isn’t being enforced, fewer healthy people are likely to buy coverage.

“Yes, the law is on books. But given the messaging from the administration, consumers won’t believe it exists,” said Sabrina Corlette, a research professor at the Center on Health Insurance Reforms at Georgetown University.

If healthy people stop buying insurance, companies will raise premiums, regardless of whether the mandate is being enforced or not.

The IRS this week made clear that it was going to step up enforcing the penalty for tax year 2017. The agency issued a statement on its website saying it will automatically reject electronic returns that don’t specify if the taxpayer had health insurance.

“The 2018 filing season will be the first time the IRS will not accept tax returns that omit this information,” the statement said.

The IRS had planned to start rejecting incomplete returns last year, but decided to delay the policy by a year because of a Trump administration executive order requiring agencies to provide “relief” from ObamaCare.

The agency’s previous policy was to process returns and follow up later with a letter to individuals.

The announcement could help stabilize ObamaCare markets, as the previous policy led to some confusion about whether the administration was trying to weaken the mandate.

The IRS said the change was being made to make it easier for people to file their taxes.