The judicial branch played an outsized role in Obama’s presidency, as his GOP critics sought to invalidate almost his entire domestic agenda.

By Sam Baker

On almost every major domestic issue—health care, climate, immigration, and more—President Obama is leaving office with a legacy defined, in large part, by the courts.

The judicial branch, and the Supreme Court in particular, has played an outsized role in shaping Obama’s presidency. Every executive is constrained by the other two branches, of course, but because Obama’s critics have turned so aggressively to the judicial branch to stop his agenda from moving forward, the courts have held disproportionate sway over the policy legacy that he’ll leave behind.

“Obama’s domestic agenda has been profoundly impacted by the courts,” UCLA law professor Adam Winkler said. “The success or failure of many of Obama’s domestic policies tuned on whether the courts upheld them.”

Obama’s most enduring political achievement was surely Obamacare and the 20 million people it has covered. It never would have gotten off the ground if Supreme Court Chief Justice John Roberts hadn’t changed his mind at the last minute and voted to uphold it.

The administration’s single biggest structural hurdle in implementing Obamacare—persuading states to accept the law’s Medicaid expansion—was also the Supreme Court’s creation. Even if Republicans fail in their effort to repeal the law under President Trump, yet another anti-Obamacare lawsuit—House Republicans’ challenge to its cost-sharing subsidies—could still do significant damage to it.

Obama’s allies are, on the other hand, more disappointed with his record on immigration. His two biggest immigration programs, known as DAPA and DACA, were relatively small and muddy solutions in the first place—consolation prizes after the failure of comprehensive immigration reform, enacted through executive memoranda with even less legal force than a regulation.

And those programs were weakened further by a similarly muddy and complex legal challenge filed by Texas—the administration’s chief legal antagonist over the past several years—that ended in a 4-4 tie last year at the Supreme Court.

His legacy on climate and energy is still partially in the judicial branch’s hands. The D.C. Circuit Court of Appeals is expected to rule any day now on Obama’s Clean Power Plan, after missing its window to make a decision before Obama left office.

Every president faces some legal challenges, especially after two terms in office. And Trump will, too—California is already preparing to play the role against Trump that Texas played against Obama.

“I think to a certain extent all of the big-policy plays eventually live or die by the hand of the courts,” said Elizabeth Wydra, president of the liberal Constitutional Accountability Center.

But, she said, Republicans did direct an awful lot of their anti-Obama energy into the courts.

“There was a very aggressive effort from the Right to try to use the courts to achieve what they couldn’t achieve through the political process,” Wydra said. “This was coming from the Right, which has previously been the party of judicial restraint, and that certainly was not the way they litigated against Obama, when they were asking the courts to be very activist in striking down federal legislation or policies.”

Republicans now have a chance to achieve some of those goals through the political process. Trump could quickly and easily end what remains of DAPA and DACA. Rolling back the Clean Power Plan, if it survives its legal challenges, would be harder, but still doable. Repealing Obamacare would be the most difficult.

Perhaps the biggest policy change of the past eight years—and the one Trump would find all but impossible to reverse—was the nationwide legalization of same-sex marriage.

“In the area of gay rights, I think the administration can take some credit,” Winkler said. “It advanced the ball a lot.”

The Obama administration helped things along, namely by deciding not to defend the federal Defense of Marriage Act before the Supreme Court. But even so, as with so much else over the past eight years, the final say rested with the Supreme Court—not the White House, and not Congress.

“The Supreme Court does like to have the last word,” Winkler said.