After the Republican Party got a bloody nose over President Trump’s shutting down of the government in attempt to get his border wall, gun-shy congressional Republicans will probably put their foot down on any attempt by Trump make good on his continuing threats to do it again for the same reason.

Thus, the impetuous president may see only one option to get money for his central campaign promise: declaring a state of emergency to raid money normally used for the country’s defenses to build the wall—even though he refrained from announcing it during the State of the Union address.

Aside from the fact that the generals at the Pentagon will not be happy with the president’s precedent for stealing their cash, any state of emergency, especially for a border wall that is likely to be ineffective in securing the nation’s southern border, is of questionable constitutionality.

Make no mistake, past presidents have declared states of emergency for various reasons, so much so that in a congressional pushback spurred by the Vietnam War and Watergate in the 1970s, Congress chose to “sunset” many of them.