Sen. Mike EnziMike EnziOvernight Finance: House votes to repeal arbitration rule | Yellen, Cohn on Trump's list for Fed chief | House passes Russia sanctions deal | GOP centrists push back on border wall funding Senators urge quotas on Canadian lumber, consultations with Congress Trump reopens fight on internet sales tax MORE (R-Wyo.) warned all along that ObamaCare wouldn't work, he says in an op-ed on

Enzi, facing a primary challenge from Liz Cheney (R), rips the law for forcing some Americans to lose their current health plans and says lawmakers who wrote the law are advocating for fixes to save their own hides.

"Those responsible for saddling the country with this law, including the law's chief salesman, President Obama, are scrambling to dodge the hammer of growing public resentment over the bill of goods that they have sold the American people. They are coming up with 'fixes,' but I caution the buyer, beware," he writes.

"The president, along with members of his party who are facing elections soon, are busy campaigning for proposals they say do what these architects of the law promised in the first place. But folks should think carefully about relying on the same people who repeatedly promised one thing and delivered something far different."

Enzi has long been an opponent of the law, though early on he was part of a bipartisan group working to find compromise on healthcare reform. Those talks collapsed before Democrats pushed through ObamaCare. Enzi points out that in 2010 he warned of many of the law's weaknesses during a Senate floor speech.

Cheney has accused him of not fighting hard enough against the law.

"The right response would have been to say: 'Absolutely not, under no circumstances.' And frankly, if all the Republicans would have done that at the beginning, had stood their ground and refused to negotiate and compromise on this, we probably wouldn't be where we are today," she said on "Fox News Sunday."

"Instead you have Republicans like Sen. Enzi who gave the president running room, and they gave him cover, and they gave him the ability to say, 'hey this is a bipartisan effort.' When in fact it wasn't; it was never intended to be."

The senator has led Cheney by wide margins in all public polls of the race.