A great deal of President Trump’s policy record — on issues like health care, energy and even immigration — would need a second term to fully take root, and could be easily reversed if he doesn’t get one.

Why it matters: Trump is doing a lot: He has upended American politics, and his appointment of conservative judges will reverberate well beyond his presidency. But if — if — he were to be a one-term president, the substantive policy changes he’d leave behind could be short-lived.

The big picture: Trump has scored few big legislative wins so far, and will instead head into 2020 with a policy record that comes largely from executive action, like regulations to expand bare-bones health insurance plans and roll back Obama-era energy standards.

But many of those actions would be at risk if he loses in 2020. (This is not a prediction that Trump will be a one-term president; only an acknowledgment that that’s 1 of the 2 possible outcomes of the election.)

A Democratic president could reverse many of Trump’s decisions just as easily as he reversed some of Barack Obama’s. Other steps that would normally be harder to reverse may not be fully cemented by January 2021.

“It’s a fairly slim record, even judging against single-term presidents, partly because the legislative achievement list is so short,” said Andrew Rudalevige, an expert on the presidency who has published books on both the Obama and George W. Bush legacies.

Trump’s economic policies are the area most likely to outlast a one-term presidency, Axios’ Dion Rabouin writes.

Undoing the 2017 tax cuts would take another act of Congress. And those tax cuts, coupled with skyrocketing federal spending under Trump, have sent annual budget deficits over $1 trillion for the foreseeable future.

But on many of the biggest domestic policy issues, his impact has been lighter.

On health care , the administration is falling short of its original ambitions. The Affordable Care Act is still standing. Several big regulatory ideas have fallen by the wayside; or won’t be finished by 2021; or are meeting resistance in the courts. Some will make it through, but their cumulative impact would be a lot smaller than what Trump once envisioned.

, the administration is falling short of its original ambitions. The Affordable Care Act is still standing. Several big regulatory ideas have fallen by the wayside; or won’t be finished by 2021; or are meeting resistance in the courts. Some will make it through, but their cumulative impact would be a lot smaller than what Trump once envisioned. On energy, too, big-picture promises of bringing back the coal industry have fallen flat, Axios’ Amy Harder writes, while many efforts to roll back Obama-era rules and other regulatory changes are caught up in delays and legal challenges.

too, big-picture promises of bringing back the coal industry have fallen flat, Axios’ Amy Harder writes, while many efforts to roll back Obama-era rules and other regulatory changes are caught up in delays and legal challenges. On trade, a Democratic president could unilaterally unwind Trump’s trade war, although it’s not clear that a President Sanders or a President Warren would want to.

Yes, but: More substantial elements of Trump’s time in office — his political impact, and most of all his reshaping of the federal judiciary — could help cement a greater policy footprint than Trump has so far secured for himself.

It’s a long shot, but if the courts do end up striking down the entire Affordable Care Act, as the Justice Department has urged them to do, that certainly would count as a health care legacy.

Similarly, on immigration, experts told Axios’ Stef Kight that Trump’s successor won’t have a hard time grappling with Trump's policies — many of those specific decisions could be easily reversed — but rather, the hardened politics in an area where compromise had once seemed possible.

“Politicians on both sides no longer feel they have permission to compromise or they don’t want to spend the political capital," said Ben Johnson, the executive director of the American Immigration Lawyers Association.

Many of Trump’s social policies also are not particularly durable on their own, but could be with an assist from the courts.

Trump has reversed or modified Obama-era rules on abortion and LGBTQ nondiscrimination, but in some of those cases Obama had reversed Bush-era rules and a Democratic president could change them yet again.

Trump’s ability to reshape the courts, however, will likely lead to a significant narrowing of abortion rights.

The other side: “Along with record job growth, rising wages, fair and reciprocal trade deals, energy independence, lower prescription drug prices, criminal justice reform, securing our border, and judicial appointments who uphold the Constitution, this president is helping America win again," White House spokesman Judd Deere said.

What’s next: Election Day is still more than a year away, and Inauguration Day is even further. That gives him time to keep trying — especially on drug prices and trade, where the White House is working hard to strike one more legislative deal.