It’s Jan. 20, 2013. This is the agenda for President Romney’s first day in office:

Demand that Congress cut corporate income taxes. Demand that Congress slash $20 billion from the budget.

Allow states to escape parts of the health-care law (if it still exists). Rewrite the way all federal regulations are issued. Call out China for cheating on international trade.

And somewhere in there find time for all the solemn rigmarole that actually makes a president a president. An oath. A speech. A parade. Some mandatory dancing. (Although because Inauguration Day falls on a Sunday in 2013, some of this ceremony could be moved to another day.)

Mitt Romney isn’t president yet, of course. He’s not even his party’s nominee, though that appears to be a virtual certainty now that his main challenger, Rick Santorum, has suspended his campaign.

But already, the candidate has laid out an ambitious 10-part to-do list for “day one” in the White House — a preview of the kind of president he wants to be. Romney imagines himself as a fast-moving executive, bold in his conservatism, with a businessman’s eye on the bottom line.

A big list for day one (or two or three) is something of a campaign tradition, a way to underline your priorities and show where your predecessor went astray.

In the first three days after his inauguration, President Obama announced orders freezing the pay of his senior staff members; rescinding the “Mexico City policy,” a ban on foreign aid to groups that provide abortions or related care; and mandating the closure of the detention center at Guantanamo Bay, Cuba — a promise that he has yet to fulfill more than three years later.

Similarly, Romney’s first-day agenda would not be as easily achieved as he suggests — on day one or, perhaps, ever. Some of his ideas seem predestined to run aground on Capitol Hill. Others could unspool huge new hassles in the federal bureaucracy.

“He’s going to discover that it is diluted a lot, because there’s a thing called a Congress and there’s a thing called a Supreme Court,” said Tom Korologos, who helped four Republican presidents — Richard M. Nixon, Gerald R. Ford, Ronald Reagan and George H.W. Bush — work with Capitol Hill.

What could Romney expect on his first day? Korologos thought of something President Harry S. Truman said about the incoming President Dwight D. Eisenhower, who was used to a general’s power: “He’ll sit here and he’ll say, ‘Do this! Do that!’ And nothing will happen.”

Still, Romney insists he could do it all.

“A lot’s going to have to happen quickly, because a new president gets elected and there’s a great deal of interest and willingness on the part of Congress and the Senate,” Romney told supporters last month in Muskego, Wis. “Let me tell you some things I’d do on day one . . .”

From there, he talked for a full five minutes. And he got through only half of the items on his jam-packed agenda.

For instance, Romney says he would submit a series of policy ideas to Congress — then “demand” that lawmakers act on them within 30 days.

One of these is the proposal to reduce the corporate income tax from 35 percent to 25 percent. That’s already a popular idea — in theory. The GOP-controlled House wants a cut. Obama wants one, too, although to 28 percent.

But nothing has happened. The problem is that legislators would need to eliminate tax loopholes to balance out the revenue that would be lost when corporate rates dropped. And in Washington, every loophole is sacred to somebody.

So how would Romney do it?

Unclear. An aide said the legislation hasn’t been drafted yet.

The devil in the details

Romney also says he would issue an Inauguration Day demand that Congress cut $20 billion from the federal budget. Which $20 billion? Here, he is also unclear.

He told the Weekly Standard that giving too many specifics would be a mistake.

“One of the things I found in a short campaign against Ted Kennedy was that when I said, for instance, that I wanted to eliminate the Department of Education, that was used to suggest I don’t care about education,” Romney said, referencing his ill-fated Senate campaign in 1994. In this case, he has specified only what would be exempt, including the military, intelligence agencies and homeland security.

“So will there be some [programs] that get eliminated or combined?” Romney told the Weekly Standard. “The answer is yes, but I’m not going to give you a list right now.”

The key to the two bills’ chances would probably be the very details that Romney hasn’t provided. Both would face long odds in a gridlocked Congress on day one.

And probably on day 100.

“He’s not going to get ’em,” said Adam Jentleson, spokesman for Senate Majority Leader Harry M. Reid (D-Nev.). Even if the Democrats lose control of the Senate in November, they will almost certainly keep enough seats to block such bills with a filibuster. “He’s not just going to wave a wand and get everything that Republicans have been seeking for two years or more.”

Another of Romney’s plans is to start rolling back the health-care law. He says he would call for issuing “waivers” to all 50 states, allowing them to escape some of the legislation’s requirements. “So we’re going to stop Obamacare that way, and then we’re going to repeal it,” Romney told the crowd in Wisconsin.

That may be unnecessary, if the Supreme Court strikes down the law in the meantime.

But if it survives, killing it may be harder than Romney lets on. The act doesn’t allow broad waivers to be issued to any states until 2017 — and then only under strict conditions.

To do more, Romney needs Congress. Which brings him back to the filibuster problem.

Complicated, even without Congress

Some of Romney’s other ideas don’t involve Congress: He would simply issue orders to the rest of the executive branch. But even these could carry maddening complications.

One idea would reimagine the way federal regulations are made. Right now, the government calculates the potential cost of implementing new rules, but it doesn’t set an annual limit on what those costs can add up to.

Romney would. And his limit would be zero.

That, experts say, could create a confusing kind of inter-government swap meet. To put in a new rule, an agency would have to find old ones that cost just as much to implement. Then, it could trade old for new.

“It has not been done, and there’s a reason for it,” said Jim Nussle, who headed the Office of Management and Budget under President George W. Bush. Nussle said it would be very difficult to measure the cost of old rules precisely, to be sure they balanced out new ones. “You’re trying to land a jumbo jet on an aircraft carrier . . . if you’re going to say, ‘It’s going to be exactly zero,’ ” he said.

Finally, Romney would use part of his first day in office to reproach China for manipulating the value of its currency. By keeping the value artificially low, Romney argues, China gains an unfair advantage with cheaper export goods.

“So I’m going to label them a currency manipulator,” Romney told his audience in Wisconsin.

But that move, by itself, would not fix the problem: Legally, it would only require the Treasury secretary to “initiate negotiations [with China] on an expedited basis.”

But some China experts say Romney would nevertheless be risking a backlash from the Chinese — over an issue that is not a top priority.

In a recent survey of the concerns of American businesses working in China, currency ma­nipu­la­tion was only the 26th-biggest worry.

“You can’t go to the Chinese and say, ‘I demand eight fundamental changes!’ ” said Derek Scissors, a China expert at the conservative Heritage Foundation. “You’ve got to pick your thing.”

Told about Romney’s choice, Scissors said: “It’s not the thing I would pick.”