Conservatives who railed against Barack Obama’s vast powers to build up the Affordable Care Act declared vindication Saturday with President Donald Trump’s executive order to tear it apart.

“For me, it’s a mix of irony and schadenfreude,” says Josh Blackman, a law professor who’s written two books that criticized the Obama administration’s implementation of the law. “I’ve warned for years that, with a new president in the White House, the exact same powers could be used for different purposes. That’s what we’re seeing now, to a T.”…

“Its implementation depended critically — and depends critically — on rules and guidance that HHS and other agencies have put out,” says Nicholas Bagley, a University of Michigan law professor who supports the ACA. “There are literally thousands of decisions that had to be made” by the administration — and “any decision that the Obama administration had the discretion to make, in principle, the Trump administration can revisit.”