“I’m willing to stand up against anyone, including members of my own party,” Walker said at Cass Screw Machine Products in suburban Minneapolis. “I’m willing to stand up against anyone to get the job done.”

Walker’s proposal calls for repealing the law immediately and replacing it with a plan that gives states more power to operate Medicaid, ties refundable tax credits to age rather than income, and shifts to discretion of states the decision on whether to offer the popular Obama provision that currently allows people up to age 26 to remain on their parents’ insurance plans.

The biggest hurdle facing the Wisconsin governor, and other Republicans calling for repeal, is getting the 60 votes needed in the Senate. The Supreme Court in June also upheld a key component of the law, a major setback for critics fighting it in court.

Walker detailed his plans with a slide presentation that mixed policy and politics, seeking both to distinguish himself from Republicans who have failed to eliminate Obama’s law, such as Sens. Ted Cruz, Marco Rubio, Rand Paul and Lindsey Graham, and to tie Democratic presidential contender Hillary Rodham Clinton to it.

“We were told by Republican leaders during the campaign last year that we just needed a Republican Senate to repeal Obamacare,” Walker said. “Well, here we sit.”

Walker’s anti-Washington argument will appeal to conservatives frustrated that Republicans leaders in the House and Senate have not moved fast enough to undo Obama’s policies. But the criticism misses the political and institutional reality: Republicans hold 54 Senate seats, short of the 60 needed to break a filibuster, and Obama can veto legislation.

Of Clinton, he added:

“As bad as things have been under Obamacare, they’d only get worse under Hillary Clinton,” Walker said.

Clinton took to Twitter to criticize Walker’s health care plan.

“16 million Americans have gained health insurance from the Affordable Care Act,” Clinton tweeted. “We need to protect it — not repeal it.”

Walker’s plan does not include cost figures or an estimate of the number of people who would be covered, making it nearly impossible to compare with current law. For the period from April to June of this year, 11.4 percent of U.S. adults were uninsured, which translates to about 16 million people gaining coverage since the rollout of Obama’s health care law in 2013.

Walker’s campaign said his plan would be paid for by eliminating $1 trillion in taxes that are levied under the current law and by making other changes to Medicaid and how health insurance is taxed.

Topher Spiro, vice president for health policy at the Center for American Progress, a think tank often aligned with the White House, said Walker’s plan would be a step backward.

“The math only adds up if he’s slashing Medicaid and increasing taxes on middle-class people with employer plans,” Spiro said.

While the Walker plan would repeal the Affordable Care Act, it appears to use some similar kinds of tools to promote coverage. For example, there would be no requirement for individuals to carry health insurance or face fines, as there is currently. But, in order to be guaranteed affordable coverage without regard to pre-existing medical problems, individuals would have to “maintain continuous, creditable coverage.”

Economist Douglas Holtz-Eakin, president of the American Action Forum, a center-right think tank, said the basics of Walker’s plan looked familiar.

“There’s a lot of this that is fairly standard conservative health policy reform,” Holtz-Eakin said.

Walker’s plan, similar to current law, would also provide tax credits to help with the cost of coverage for people whose employers don’t offer insurance. But unlike current law, those credits of between $900 and $3,000 would be based on age and not be keyed to a person’s income. So they may not help low- to moderate-income people as much as the existing tax breaks do.

The Congressional Budget Office has said that outright repeal of the Affordable Care Act, as Walker wants to do, would kick 19 million people off insurance in the first year.

Walker isn’t the first Republican to put forward a detailed plan for replacing Obama’s law. Louisiana Gov. Bobby Jindal released his plan last year and Rubio outlined his approach in an opinion piece published Monday. And while alternatives have been introduced in Congress, none has gotten traction as Republicans have yet to coalesce around any particular idea.