WASHINGTON ― Only in America could a billionaire developer and TV star be an “outsider.” But that is how Donald Trump marketed himself, winning the Electoral College thanks in part to rural white voters who accepted his lies and loved his loathing of the Establishment.

On Tuesday, at 9 p.m. EST, Trump is set to take his outlaw act to the very heart of the federal capital and its culture. As he addresses his first joint session of Congress, he will literally be surrounded by leaders of the institutions and forces he claims to despise ― people whom he now needs to harness, or at least pacify, if he is to succeed.

How will he behave, and what will he say, in the belly of the beast?

His first five weeks as president have been, frankly, a mess. True, he has made a start ― largely symbolic ― on implementing some of his anti-regulatory and anti-immigrant ideas, following the pattern of his predecessor in using executive orders.

But at the same time, Trump has fought a war with the press, with his own staff, with the bureaucracy in general and the intelligence community in particular, with foreign allies, with a federal appeals court ― and with himself, if his bizarre, stream-of-consciousness press conference this month is any indication. He has emitted a steady stream of boasts, “alternative facts,” accusations and outright lies as he struggles to gain traction ― and at this point in his term, he has the lowest approval rating of any president since Eisenhower.

Even his friends doubt that this is the way to get the job done in Washington.

“He knows it’s been a rocky start in some ways,” said a close friend who has known Trump for years, and who declined to be quoted by name so he could be frank. “I think he’s trying to do too much, on too many fronts. But Donald is a guy who does not know how to lose. He’s going to figure the thing out, believe me.”

If he is, Tuesday evening will be his best chance to start. Joint sessions are relics of another era. But their TV audiences are often huge, which is all the more important in a fragmented media world.

Here’s what you have to understand, Donald, if you hope to use tonight to launch your agenda in Congress and in the country as a whole:

1. This isn’t WWE. Democrats are on to your game. They will try not to play it tonight. Rep. Dan Kildee (D-Mich.), who leads the Democrats’ floor-messaging operation in the House, told me that his troops have been warned not to let you turn the evening into a shouting, name-calling, political wrestling match. “Will someone shout ‘you lied,’ like Joe Wilson did years ago at Obama? Maybe, but I hope not,” Kildee said. “We can’t give him an excuse to turn the thing into political theater.”

2. You aren’t the boss ― you’re the apprentice. You are the oldest person ever elected president, and the only one with no governmental experience of any kind, either in elective office or in the military. There are people in the room who can actually help you, if you let them.

Yes, you were elected in part because you sold the notion that ignorance of the System is a virtue ― that’s what we all said as college kids in the ‘60s! ― but that can’t and won’t work in the Oval Office.

3. You are not Ronald Reagan. The Gipper was a master of using TV to “go over the heads of Congress” in the early 1980s, using his forceful yet genial personality to put public pressure on lawmakers. But those were the days of “Reagan Democrats,” and Reagan’s appeals had a bipartisan effect. You have no purchase whatsoever with Democrats today, and very little at the moment with independents. You can firm up the GOP base, but that is already 85 percent in your corner, according to the polls.

4. You don’t own the GOP; you are renting it. From the Conservative Political Action Conference to the cloakrooms of the Hill, Republicans and conservatives are impressed, even intimidated, by your salesmanship. But they’re also suspicious of your motives and your actual beliefs. House Speaker Paul Ryan (R-Wis.) is not going to forget that you tried to destroy him. Senate Leader Mitch McConnell (R-Ky.) was desperate to back anyone but you in 2016, and regards with horror your idea of managing the presidency with tweets. The poll numbers and threats to go after recalcitrant Republicans will keep the party in line – until the moment they don’t.

5. You’re going to have to “own” health care. GOP leaders and rank-and-file members want to hear details about how you’ll “repair and replace” Obamacare. The health care law isn’t wildly popular, but it’s still more popular than dismantling it outright would be. Calling the matter “complicated” doesn’t get you off the hook. Republicans’ interest isn’t just idle curiosity: They want political cover, and that means details from you.

6. Corollary: You need to be Bismarck, not Putin. Without calling it such, your vision of America is essentially a Daddy State ― nationalistic, border-closing and xenophobic, yet generous and concerned with the welfare of citizens and immigrants who profess their “love” for this country. If that is your model, you have to deliver. In the 19th century, Otto von Bismarck pioneered social insurance in part as a means of unifying Germany. It’s still a potent idea.

Russia, though, is the opposite story. From Lenin to Putin, leaders there have claimed to offer cradle-to-grave care, but with disastrous results, then and now. That means you actually have to protect Social Security, Medicare and, yes, even the Medicaid portion of Obamcare in full.

7. You can’t cook the books. The federal government isn’t a private family corporation, and you almost certainly can’t turn it into one. You can’t preemptively sue congressional committees to keep the real numbers away from them. You’ll most likely install pliable people atop the agencies that keep track of the figures, including the Office of Management and Budget, the Department of Labor and elsewhere. But the budget is too vast, and the machinery that keeps track of it too complex, for you to get away with cooking the numbers. (Let’s be honest: It didn’t really work in Atlantic City, either.) That means the budgets you propose, both the “skinny” first one and the fatter second one, will need to add up ― and they’ll show big deficits.

8. You can’t govern as the heel. Yes, you came this far by being the hero people love to hate. In wrestling terms, you like being the “heel.” Your theory is that you can’t ever get 100 percent of the market, and that in a lethargic and cynical country, a fervent minority of voters is all you need to win. It worked in 2016, and you might think it could work now, since the GOP has a majority in both chambers. But simply bullying Republicans to keep them in line won’t be enough.

For one thing, it’s not clear that McConnell is going to destroy the filibuster altogether, which means you will need 60 votes – including Democrats. For another, the GOP is not wholeheartedly behind you. And Americans like to like their president. It’s what presidents are for.

You can’t govern solely with your own party, even though Barack Obama was often forced to do so. This is not a parliamentary system ― it is a presidential system with deliberate separation of powers. We need a president who seeks the moral authority to lead all of the people. Start acting like that kind of president. Tonight.