In the constitutional confrontation over President Trump’s plan to use emergency powers to build a wall on our southern border, we’re keeping an eye out for the name of Jagdish Rai Chadha. He was the plaintiff in the case in which the Supreme Court read Congress the riot act for trying to interfere with a president’s emergency powers. The case echoes through the years.

At the moment, the President is being opposed by Speaker Pelosi, Senator Schumer, Congresswoman Ocasio-Cortez, and every other Tom, Dick, and Harriet in the Democratic Party. Sixteen states have already gone to court. They’re complaining about what they call Mr. Trump’s “flagrant disregard of fundamental separation of powers principles engrained in the United States Constitution.”

This turns out to be exactly the principle with which the Justices clobbered Congress in INS v. Chadha. In that case, decided in 1983, the president used emergency powers to permit Mr. Chadha, a stateless person who had overstayed a student visa, to remain at America. The House of Representatives turned around and “vetoed” the suspension.

When it got to the Supreme Court, the Justices would have none of it. Congress, the justices concluded, doesn’t get to veto what a president does. Feature the parchment. The veto, as a power, is granted in the Constitution to only the president. He gets to use it against Congress. Nowhere does it say that the Congress gets a veto against the President.

When it comes to dealing with a president, the House can impeach the muskrat, the Senate can try him, Congress can refuse to appropriate money, it can declare war, it can grant a trademark. It can repeal a law. Veto, though, no. In the case of Mr. Chadha’s deportation, moreover, it was just the House of Representatives, acting alone, that tried to veto the president’s emergency action.

This hangs out there today, when we have a Senate controlled by the GOP and the House by the Democrats. “One-house legislative vetoes are invalid because they should be considered an exercise of legislative power, which makes them subject to the bicameralism and presentment requirements in Article I of the Constitution,” is the way the Justia Web site summarizes the case.

The business about presentment means that if Congress were trying to legislate around a presidential emergency action, the president would get to sign off on it, just like any other act by Congress. This is one of the checks and balances to which everyone is always bowing and scraping. It looks like a problem Congress could face as she seeks to foil President Trump in respect of the Wall.

There is, though, one glimmer of constitutional hope for the House. It lies in the fact that Chadha was not unanimous. The majority of seven justices who sided against Congress comprised the liberals on the Court — Chief Justice Warren Burger, Justices Thurgood Marshall and John Paul Stevens among them. The two justices who sided with the House, Wm. Rehnquist and Whizzer White, were conservatives.

The conservatives configured that the Congress had “never been disposed to give the Executive Branch a free hand” in the first place. That, though, might be a hard case to make in respect of the National Emergencies Act. That’s the law under which Mr. Trump is acting. It passed the House in 1975 by a vote of 388 to five. It’s going to be hard to suggest that Congress was divided.

That doesn’t mean the states have no chance at a victory, particularly in the lower courts, where every joey on the bench seems eager to enjoin the president. Announcing in the Rose Garden his plan to use emergency powers, Mr. Trump made clear that he expects a long court battle. One’ll get you ten his camarilla knows all about Chadha.