During the US presidential campaign, Mr Donald Trump pledged to "cancel every unconstitutional executive action, memorandum and order issued by President (Barack) Obama".
The good news was that Mr Trump did not simply use the phrase "executive order" to describe every administrative tool presidents can use. That simplification is inaccurate.
The bad news was that it wasn't clear, then or now, which particular actions he deemed "unconstitutional". Many of those he complained most about on the campaign trail - about gun control, for instance - had little substantive impact on gun ownership or use.
In any case, judging from his recent YouTube video announcing his own plans for "Day One" of his administration, Mr Trump sees executive actions exactly as other presidents have: as a means to show leadership and to push forward his policy preferences fast, without the tedium of the legislative process. (In his 21/2-minute video, Mr Trump never used the word "Congress", though other items from his campaign's "100-day plan" would clearly need legislative approval.) The items in his list range from things clearly within the president's unilateral authority to those that will require a fair bit of cooperation from others.
In the first category: asking departments to look at things. One of the less-touted Article II powers, after all, is the president's ability to "require the opinion, in writing", of his department heads.
Repealing an existing regulation requires a rulemaking process of its own, subject to the Administrative Procedure Act - this can take months or years.
For instance, Mr Trump says he will have the Department of Labour investigate visa abuses "that undercut the American worker". And he will ask the Department of Defence and the Joint Chiefs of Staff to develop a "comprehensive" plan to protect American infrastructure against cyber and "all other forms" of attacks. (Though, given the US$575 billion (S$819 billion) or so spent annually at the Pentagon in recent years, it's fair to hope that such a plan already exists.)
Also easy to do: withdrawal from the Trans-Pacific Partnership, the trade deal that came in for bipartisan bashing during the presidential campaign. Since the TPP has not been sent to Congress for its approval, Mr Trump can readily decide to continue not sending it.
Replacing the TPP with "fair" bilateral agreements is harder. The power "to regulate commerce with foreign nations" is given explicitly to Congress in Article I, Section 8, of the Constitution, but the negotiation of trade arrangements is indeed left to the president, usually through the Office of the US Trade Representative.
Congress renewed so-called "fast track" negotiating powers in 2015 until at least 2018. That makes legislative approval easier to get, but not inevitable. And however fast the Trump administration tracks such talks, nothing will be in place on "Day One".
Mr Trump's ethics proposals, likewise, foresee a two-step process. He can certainly make his job offers conditional on appointees (even the lobbyists) agreeing to sign a five-year or lifetime ban on lobbying after they leave the administration. But it won't be legally enforceable unless that prohibition is put into statute, which of course requires Congress.
In his talk, Mr Trump stressed the need for regulatory relief. He will, for instance, "cancel job-killing restrictions" on the production of US energy. (The ones easiest to cancel, though, apply only to federally owned land. He could also streamline the approval process for projects like the XL pipeline. It's not clear that either would produce the promised "millions of jobs".) Mr Trump also said he would require the elimination of two existing regulations whenever a new regulation is proposed.
This sounds appealing. It's relatively straightforward to stop regulations that are not yet finalised as of Jan 20. Mr Trump could also decide not to defend Obama rules that are being held up in court - dealing with overtime pay, for instance.
But then things get more complicated. Repealing an existing regulation requires a rulemaking process of its own, subject to the Administrative Procedure Act - this can take months or years. The Supreme Court has held that a rule can't be rescinded simply to reduce regulation; there has to be "a reasoned basis for the agency's action". At least some of the low-hanging fruit of the regulatory underbrush has been cleared by various presidents' efforts to deregulate. For instance, Mr Obama has claimed that his "look-back" initiative aiming to "identify and reduce regulatory burdens" saved more than US$13 billion by 2014.
More important, the issuance of regulations is often required by law - and the power to write those regulations is normally vested in a given department or agency, not in the White House. Presidents cannot unilaterally veto a regulation that an agency is determined to issue, or repeal one an agency is determined to keep.
For 40 years, presidents have been frustrated with that fact, leading to escalating administrative workarounds. Since the Nixon administration - but far more systematically under president (Ronald) Reagan and his successors - presidents have sought to monitor, amend, and/or delay (sometimes to death) agency proposals to regulate. They have required agencies to conduct formal cost-benefit analysis to make sure a rule's benefits justify its costs, and interposed the Office of Information and Regulatory Affairs (OIRA) to review "significant" rules and enforce presidential priorities.
All this has been controversial. Scholars note that OIRA civil servants are "ideologues for efficiency" without a particularly partisan agenda. But during the Reagan-Bush years, congressional perceptions that OIRA was being used to usurp departmental powers led to a decade-long battle that might now be rekindled. The president will, of course, choose political appointees loyal to his agenda, and can punish - even fire - any who resist his deregulation efforts. But those tactics come with their own political costs, especially where regulation is actually popular.
Thus, one key to all this rests in Congress. Will eight years of Republican objections to "executive overreach" still apply when a Republican president takes the same actions? Will Democrats who cheered Mr Obama's willingness to end-run legislative gridlock now object to presidential directives?
The likely answers: no, and yes. For most political actors, presidential power is bad only when it is exercised by a president of the opposing party. There's been a lot of change in American politics recently - but it's a good bet that this particular form of bipartisan hypocrisy will remain constant.
• The writer is Thomas Brackett Reed Professor of Government at Bowdoin College. He specialises in the study of American political institutions, primarily the presidency and the interbranch relations, with a recent focus on presidential management of the executive branch.