Heritage Foundation President Jim DeMint fired back at critics of the Tea Party-led effort to dismantle the Affordable Care Act in an op-ed in The Wall Street Journal on Friday.

“Full legislative repeal may not be possible while President Obama remains in office,” DeMint wrote. “But delaying implementation by withholding funds from a law that is proven to be unfair, unworkable and unaffordable is a reasonable and necessary fight.”

Critics, including many in the Republican Party, have blasted Sens. Ted CruzRafael (Ted) Edward CruzTexas Republicans slam White House over disaster relief request Dem rep: Trump disaster aid request is 'how you let America down again' Moore endorsements disappear from campaign website MORE (R-Texas) and Mike LeeMichael (Mike) Shumway LeeProminent conservative passes on Utah Senate bid Johnson says he will not support tax-reform bill Moore endorsements disappear from campaign website MORE (R-Utah) for their push to defund the president’s healthcare law. Cruz and Lee led the fight, which provoked a government shutdown, and left many questioning their motives and tactics.

DeMint, who supported the senators' efforts, said "we will continue to fight" because it's necessary "to protect the American people from the harmful effects of this law."

Republicans have taken a hit in the polls because of the shutdown, but DeMint said the budget battle was a win for conservatives because it enabled the GOP to lock in sequester-level spending cuts and kept ObamaCare at the forefront of political debate.

“If the Republicans had not fought on ObamaCare, the compromise would have been over the budget sequester,” he said. 

“Instead, they have retained the sequester and, for the past three months, ObamaCare and its failings have been front and center in the national debate. Its disastrous launch was spotlighted by our defund struggle, not overshadowed, as some contend. With a revived and engaged electorate, ObamaCare will now be the issue for the next few years.”

Heritage has been in the crosshairs of some in the GOP, who believe the conservative think tank is fanning the flames of dissent within the Republican Party by encouraging the Tea Party to buck the establishment.

On Thursday, Sen. Orrin HatchOrrin Grant HatchProminent conservative passes on Utah Senate bid Republicans offer this impossible choice: Tax cuts or senior care Senate GOP running out of options to stop Moore MORE (R-Utah) said Heritage was in danger of “losing its clout” for taking a hard line in efforts to repeal the law.

“Heritage used to be the conservative organization helping Republicans and helping conservatives and helping us to be able to have the best intellectual, conservative ideas,” Hatch said.

"There's a real question on the minds of many Republicans now — I am not just speaking for myself, for a lot of people: Is Heritage going to go so political that it really doesn't amount to anything anymore?' ” he continued. “I hope not. I'm going to try to help it survive and do well. Right now, I think it's in danger of losing its clout and its power around Washington, D.C."

In DeMint’s op-ed, he laid out the conservative argument for why the fight against ObamaCare was as important as ever. He said “Americans are getting notices in their mailboxes every day” about rising premiums. He said “the cost of ObamaCare’s new entitlements” would lead to a debt crisis and argued that the law in its current form “will lead to a single-payer healthcare system.”

DeMint also dismissed the notion that ObamaCare was a settled issue with voters, arguing that it wasn’t “the central fight” in the 2012 election.

“ObamaCare was not the central fight in 2012, much to the disappointment of conservatives,” he wrote. “Republicans hoped that negative economic news would sweep them to victory, and exit polls confirmed that the economy, not healthcare, was the top issue. The best thing is to declare last year's election a mistrial on ObamaCare.”