Sen. Bill Cassidy's legislation to overhaul Obamacare was endorsed in President Trump's budget on Monday, but the Louisiana Republican said Congress is unlikely to act unless a groundswell of opposition to the law forces Democrats to come to the table.

Cassidy, speaking during a meeting Monday with the Washington Examiner’s editorial board, suggested it was unlikely that Republicans would make another effort at passing major healthcare legislation on a purely partisan basis, having failed several times last year to deliver on their long promise to repeal and replace Obamacare.

Though it is still theoretically possible for Republicans to repeal Obamacare with a simple majority, he is not betting on that happening. For one thing, doing so would require Republicans to pass a budget, which remains very much in doubt.

“Right now the healthcare issue does not have a swell of concern beneath it,” he said. “You do major policy when there is a swell of concern and people are looking for a solution and you have thought out a solution.”

Cassidy said that groundswell could start as states begin to shoulder more of the financial burden of Obamacare's Medicaid expansion. Though it was fully funded by the federal government initially, states are starting to gradually take on more of the costs, and by 2020 they will have to cover 10 percent of the expanded Medicaid.

“Do I think that states are going to come to the federal government and at some point say we can’t afford our Medicaid programs? Absolutely,” Cassidy said, noting that a number of states are already struggling.

Cassidy said that while Obamacare as a whole remains, Republicans did repeal central pillars of the law, including the penalties for individuals who don't purchase health insurance starting in 2019.

However, the bill Cassidy sponsored alongside Sen. Lindsey Graham, R-S.C., failed to get enough support from Republican senators when it was introduced back in September. More centrist GOP senators including Sens. Susan Collins, R-Maine, and Lisa Murkowski, R-Alaska, were worried about the Medicaid cuts and conservatives such as Sens. Mike Lee of Utah and Rand Paul of Kentucky feared it kept too much of the law's taxes, spending, and regulations intact.

Graham-Cassidy would convert Obamacare's funding for the Medicaid expansion and subsidies toward the purchase of insurance to block grants, providing more flexibility to states. It would also seek to restrain Medicaid spending by giving states a fixed amount per beneficiary and controlling its rate of growth.

Cassidy said that he hopes to get traction on legislation to establish more transparency over healthcare prices, both for pharmaceuticals and for healthcare procedures such as CT or MRI scans.

"We have a bill we are probably going to introduce this week or next week on price transparency," he said.

Cassidy is also working on separate legislation to address a "gag order" that prevents pharmacists from telling customers that it is cheaper to pay for a drug out of pocket than through their insurance.