By Robert Romano

Whatever can be done with executive action can be undone by executive action.

That was one of the messages outgoing President Barack Obama had for his successor, President-elect Donald Trump in an interview with NPR, where Obama said, correctly, that “If he wants to reverse some of those rules, that’s part of the democratic process. That’s, you know, why I tell people to vote — because it turns out elections mean something.”

So, suddenly, upon assuming office, Trump could start immediately rescinding controversial executive actions, whether Obama’s executive amnesty for millions of illegal immigrants with U.S.-born children, or his decision to close the Guantanamo Bay detention facility.

In total, Obama has issued 260 executive orders. Those could all be rescinded on day one, as there is no legal requirement they be retained.

There’s also a bevy of regulations, including the 2009 Carbon Endangerment Finding by the Environmental Protection Agency and its corollaries, the new and existing power plant rules, that constituted the agency’s expansive war on coal electricity.

There are labor regulations, including the overtime pay rule or the persuader rule.

There was the Affirmatively Furthering Fair Housing rule that conditioned the receipt of community development block grants on municipalities making changes to local zoning along racial and income guidelines.

Those could be rescinded by the agencies that issued them, through the process under the Administrative Procedures Act, which could take a couple of years. Best to get started right away.

There is also the Congressional Review Act (CRA), which gives Congress the power to roll back with simple majorities regulations within 60 legislative days of being implemented. That goes back to June, and according to the Heritage Foundation, includes “many dozens of major rules [that] could be vulnerable to a CRA challenge. These include, among others: Rules under the Dodd–Frank financial regulation law, Sick leave for federal contractors, Offshore drilling rules, and Energy mandates for home appliances.”

It would also include a bevy of midnight regulations now being implemented at lightning speed, said to cost $6 billion.

Then there is Obama’s executive action to indefinitely seal off much of the outer continental shelf in the Atlantic and Arctic Oceans from oil and gas drilling. Obama officials are bragging that this is one action that cannot be undone by executive action, although there is a clear process under the law for issuing new offshore drilling leases.

But even if an attempt to undo Obama’s action to block drilling via executive action got caught up in federal court, Congress could always just defund it or pass new legislation repealing the provision he invoked.

Speaking of which, Congress could always defund, or prohibit the use of funds to implement regulations and any other executive action. So, where all else fails — if for example litigants manage to preserve certain regulations and other actions via federal court mandates — there is always the budget and the power of the purse where Congress can intervene.

With that in mind, Congress could act preemptively, and defund what it can in the April continuing resolution, particularly controversial items the left is likely to sue over, to strengthen the President’s hand.

A lot can be done to undo Obama’s legacy, and Trump will be in the driver’s seat. Ironically, not so much action is required by Congress. Which, really, is Obama’s fault, since he relied on executive action so much during his tenure.

If Trump washes away Obama’s legacy, ending implementation of a scores of Obama executive orders, actions and regulations, they will be wiped away like a dry erase board—and Obama will have nobody to blame but himself for acting unilaterally to begin with.

Robert Romano is the senior editor of Americans for Limited Government.