President Trump’s decision to declare a national emergency in order to fund his border wall triggers a crisis for our Constitution and our democracy. This is no longer about the shameless lies, exaggerations and slanders that the president has trotted out to justify his silly campaign promise to build a wall that he promised Mexico would pay for.

It’s no longer about wasting billions of dollars, of shutting down much of the government for weeks or squandering the time and attention of the Congress and the American people for an inane campaign promise. 

President Trump now poses a fundamental challenge to our democracy: Does Congress have the essential power of the purse that the Constitution gave it, or can a president at his whim declare a national emergency and spend what he wants on what he wills? This is the line between a constitutional republic and a presidential autocracy.

President Trump’s petulant response to not getting the money he wants puts that question before the Congress and the courts. President Trump wants money for the wall. Congress — both the Republican Senate and the Democratic House — voted not to give him as much as he demanded. So the president declares a national emergency and uses money appropriated by the Congress for other purposes to fund his wall. Only there is no national emergency.

Congress and presidents have been debating and legislating about our immigration policy and about border security for years. Contrary to the president’s hysterical lies, arrests for illegal entry have declined. With the economy near full employment, there is no economic crisis sparked by undocumented workers. Contrary to the president’s claims, the wall won’t stem the flow of illegal drugs into America, the vast bulk of which come through legal ports of entry. 

Even the president in his White House Rose Garden news conference last week admitted that he didn’t need the money; he just wanted to build the wall faster. All we have is a normal dispute between a president and a Congress about spending priorities. 

President Trump is saying that since he can’t get what he wants, he’ll simply do it on his own. That effectively erases the congressional power of the purse, a foundation of a constitutional republic. If President Trump’s decision is upheld by the Congress and the courts, a chilling precedent will be set. 

Most Americans agree with the Congress and don’t support wasting money on the wall. Declaring a national emergency to build it is even more unpopular. When the White House invokes eminent domain to take over hundreds of miles of privately owned land on the border, public opposition will grow. But what will stand in the way of a willful president? Under the National Emergencies Act of 1976, passed by Congress after Watergate to curb presidential abuse of national emergency declarations, the Congress can reject the president’s declaration.

The House, with its Democratic majority, surely will vote to reject. Republicans in the Senate will then have 15 days to decide whether they are prepared to back President Trump or stand up for our republic against the president, his Fox TV allies and the right-wing echo machine. If the Senate rolls over, or the president vetoes the rejection, the issue will end up in federal courts, many packed with right wing activist judges appointed by President Trump. 

Right wing judges normally are skeptical of exaggerated claims of executive power, worried that they will be used by liberal presidents to expand the public sphere. But increasingly, these judges have put partisanship over constitutional precedent and their own judicial philosophy. Most recently, for example, in Trump v. Hawaii, the right wing gang of five on the U.S. Supreme Court voted 5-4 to overrule the lower courts and to uphold the president’s Muslim travel ban, emphasizing the need to show “deference” to presidential authority in matters of immigration and national security. 

If the Senate folds and the courts roll over, we will be well on our way to an elected autocracy. Many people treated President Trump’s posturing over the wall as a diversion, a low-rent, off-color vaudeville act used to rouse his audiences. The racial and ethnic slurs that he spreads always made it more poisonous than that.

Now his declaration of a national emergency has turned it into a direct assault on our democracy. Now we will see who stands with the Constitution, and who does not.

The writer is founder and president of the national Rainbow PUSH Coalition.