What would a second Trump presidency look like for health care?

On the presidential campaign trail, former President Donald Trump is, once again, promising to repeal and replace the Affordable Care Act — a nebulous goal that became one of his administration's splashiest policy failures.

"We're going to fight for much better health care than Obamacare. Obamacare is a catastrophe," Trump said at a campaign stop in Iowa on Jan. 6.

The perplexing revival of one of Trump's most politically damaging crusades comes at a time when the Obama-era health law is even more popular and widely used than it was in 2017, when Trump and congressional Republicans proved unable to pass their own plan to replace it. That failed effort was a big part of why Republicans lost control of the House of Representatives in the 2018 midterms.

Despite repeated promises, Trump never presented his own Obamacare replacement. And much of what Trump's administration actually accomplished in health care has been reversed by the Biden administration.

Still, Trump secured some significant policy changes that remain in place today, including efforts to bring more transparency to prices charged by hospitals and paid by health insurers.

Trying to predict Trump's priorities in a second term is even more difficult given that he frequently changes his positions on issues, sometimes multiple times.

The Trump campaign did not respond to a request for comment.

Perhaps Trump's biggest achievement is something he rarely talks about on the campaign trail. His administration's "Operation Warp Speed" managed to create, test, and bring to market a COVID-19 vaccine in less than a year, far faster than even the most optimistic predictions.

Many of Trump's supporters, though, don't support — and some even vehemently oppose — COVID