It’s happening.

Shortly after 10 this morning, President Donald Trump announced that he’s declaring a national emergency so he can build his wall and “stop criminals and gangs from coming into our country.” Also, he said, it’s a “great thing to do.”

Trump has apparently convinced himself that declaring a national emergency is the only way out of the box that he and Republicans had two years to make Mexico pay for. Perhaps this move will appease the true executive authorities in the United States: Sean Hannity and Ann Coulter. But creating a real constitutional crisis to legitimize a fake border crisis will still not bring Trump any closer to his vanity wall.

There are three obvious responses that could stop Trump’s national emergency. That’s in addition to the nearly infinite ways a concerned and dedicated citizenry can stop a 250-mile-long metaphor from being built across the southern border. (For God’s sake, Queens just stopped mighty Amazon from building a warehouse using old-fashioned grassroots organization, amplified by mean tweets from AOC.) But there are three immediate ways, one in Congress and two in the courts, to put an end to Trump’s emo rebellion against Speaker Pelosi before one steel slat is erected. And they’re all very legal and very cool.

There’s still this thing called Congress.

Much has been made of the near-tyrannical grant of powers contemplated in the National Emergencies Act of 1976. Once the NEA is invoked, the president must list the powers he or she is invoking for themselves, and those powers can be quite sweeping. A president could, theoretically, commandeer the Internet or prohibit transactions with foreigners. After 9/11, and the emergency declared because of it, George W. Bush authorized sanctions against any US citizens suspected of giving aid to designated terrorist.

You can see why people are freaked out. Trump is a vindictive, racist man. If he can find a way to attack any citizen who ever gave a hungry brown child a bowl of soup, he probably will.

As it is, there are 31 “national emergencies” still in effect—out of a total of 58 that have been declared over the years—and, upon reflection, most of them are dumb. All the emergencies represent a creeping aggrandizement of executive power over an apathetic Congress. I wish I had listened to George Will when he tried to tell me that in college, but I was too busy being horrified by his unwillingness to use federal power to stop states’-rights racism.

Despite these 31 gallons of spilled milk, Congress remains a co-equal branch of government. As such, it has the authority to terminate a national emergency declared by the president—it’s right there in statute.

Congress can end Trump’s emergency by passing a joint resolution to terminate it. That resolution has to pass both houses of Congress, and must be signed by the president. But, and this is the fun part, if the House passes such a resolution, the Senate must schedule it for a vote. And if it fails in the Senate, there must be a conference committee to hammer out the differences, and then that resolution must be voted on.

This is important, because one of Mitch McConnell’s favorite antidemocratic tricks is to prevent bills from coming to the floor that force Republicans to risk angering Trump. That won’t work this time. If the House passes legislation terminating the emergency (which Nancy Pelosi can do after 15 days of the declaration of said emergency), then the Senate has to take it up.

Republicans are cowards and hypocrites, so they might well decide to vote for a tyrannical overreach of government power in an act of supplication to Trump’s shrieking-while-shrinking base. Even if it passes, Trump can veto the joint resolution, which will trigger a veto-override vote, requiring additional Senate Republicans to break from the president. I doubt that there is enough strength left in the Republican Party to do this work, but congressional action is the first and most obvious way to protect the norms of democratic self-government.

Is it a “real” emergency?

Make no mistake, all but the dumbest Republicans do not want this national-emergency thing to be a thing. They know that if Trump gets away with this, the very first thing that happens when there is a president who actually wins the popular vote is a “national emergency” to combat climate change. Trump has already made this power such a part of the public consciousness that the climate-change emergency (which is, you know, a real one) has already cemented itself as one possible option in the next president’s toolbox.

Republicans are hoping the courts bail them out on Trump’s emergency, and in so doing stop the progressive ones of the future. Luckily for them, lawsuits challenging Trump’s emergency will be filed almost instantaneously after he declares one. The nonprofit Protect Democracy has already indicated that it has a plaintiff and has prepared its challenge.

Protect Democracy will represent the county of El Paso, Texas. That’s significant, because El Paso is perfectly situated to argue that there is no “emergency.”

There is scant precedent on what constitutes a “real” emergency and what does not, but there must be a difference between the two. If you look at the 31 current “emergencies”—which, again, are stupid—you’ll note that most of them deal with some kind of foreign malefactor. That makes sense; the president is on his or her strongest executive footing when he or she is responding to terrorism or blocking foreign operatives from using American banks to launder money.

There’s no national emergency for “too many brown people” or “Nancy Pelosi isn’t nice to me.” The foreign malefactor here is… Guatemala? A mother seeking asylum in accordance with international human-rights practices? Mexico, for not paying Trump’s campaign promises?

By suing, Protect Democracy will force the Trump administration to describe what, if anything, the “emergency” is and provide some kind of “evidence” that it exists. When you can force the Trump administration to have to “prove it,” they usually fail. This lawsuit really should work.

If so, can it violate separation of powers?

Of course, that’s what I said about the Muslim ban. I will never again underestimate the ability of Chief Justice John Roberts to declare that the president has a constitutional right to be racist. It’s entirely possible that a conservative court will say that the president can declare a national emergency for any reason, real or not, bigoted or not, and we all just have to deal with it.

But this fake national emergency includes a wrinkle that the Muslim ban did not: It’s a clear violation of the expressed authority of Congress to appropriate funds.

Put it like this: Trump couldn’t declare a national emergency, revoke the 13th Amendment, enslave black people, and force them to build his wall. We all get that, right? (I wasn’t asking you, Steve King.) There is some limit to the president’s powers, even under an emergency, and that limit must be reached when he violates other expressed provisions of the Constitution. We have to assume the National Emergencies Act was written with the rest of the Constitution in mind.

The Constitution expressly hands the appropriations power to Congress. And Congress, expressly, did not appropriate funds for this wall. Calling Congress’s exercise of its power the “emergency” that allows the president to ignore congressional authority simply cannot be what the NEA was written to do.

Another useful thought along these same lines is what lawyers call “nondelegation doctrine.” It means that Congress cannot give away the powers the Constitution requires it to perform. Every parent knows what I’m talking about: “No, Junior, you can’t give your vegetables to the dog… No, I don’t care if the dog is hungry.” Courts are supposed to interpret the NEA in a way that doesn’t allow Congress to give up its “essential legislative functions,” and spending money is pretty much the only thing Congress is good at.

There is precedent for my view that the authority Trump purports to wield here is total madness. The case is Youngstown v. Sawyer. It’s the case where Harry Truman tried to nationalize the steel mills to stop a steel-workers strike. The Supreme Court ruled that Truman exceeded his authority.

The most relevant part of that decision was a concurrence written by Justice Robert Jackson. Jackson helpfully outlined how the Court should think about executive power, and noted that the executive’s power is at its “lowest ebb” when he takes actions against the “express or implied” will of Congress.

You know who remembers that case? John Roberts. I know he remembers it because he quoted Jackson’s lines in the Youngstown case at his own confirmation hearings.

A challenge—and this challenge could be completely separate from what El Paso is doing, and started in a different lower-court system—to Trump’s “emergency” that argues that said “emergency” exceeds his executive authority and violates the constitutional separation of powers has to succeed, or this entire concept of co-equal branches of government has been a lie all along.

And here’s the crux: These are just the death blows to Trump’s emergency that I can think of off the top of my head. I don’t even have to get into the eminent-domain issues that will stymie Trump’s attempt to get the land, or the environmental-impact studies the government is required to do before erecting a structure that’s going to change flood patterns and cut through wildlife reserves and murder butterflies.

The National Emergency to Steal Money to Build the Wall That Mexico Didn’t Pay for so I Don’t Look Like a Fool on Fox News is not a legal thing. Congress can stop it. The courts can stop it. The Constitution demands that it be stopped.