In Youngstown, the Court found that President Truman violated the separation of powers by seizing the steel mills, without Congressional authorization. In an alternate reality, could Congress have brought articles of impeachment? Sure, you can bring articles of impeachment. The most interesting question is whether the Senate would have been correct to remove him. Is a Supreme Court decision finding the President violated the Separation of Powers conclusive evidence that the President was guilty of “high Crimes and Misdemeanors.” Of course the Senate would be able to decide for itself whether the President acted lawfully, but a Supreme Court decision would be probative.