Knowingly violating the Constitution

and the Presidential oath.

Of course most Presidents do this- they take actions that they know are beyond the scope of their delegated powers. I can think of examples from Trump (clearly reallocating money to the border for projects Congress had specifically declined to fund), Obama (stating repeatedly that he did not have the constitutional authority to grant amnesty for the Dreamers and then going so), and Bush (signing a campaign finance bill while stating that parts of it were unconstitutional). I don't think that impeachment and removal is or would have been the prudent reaction to these actions. But discussion of impeachment for willfully violating the constitution and the Presidential oath seems appropriate.

But Congress has no appetite to push back and defend what should be their turf. In fact, they would prefer to do the opposite since most of Congress has no interest in legislating.