^ Violating the emolument clause is a bit harder to prove than Obstruction of Justice in that you'd have to prove that his Russian revenues ultimately come from Puti-Put and not his surrogates, and that they're intended to affect policy. Not impossible to prove, of course, but harder that Obstruction.
_________________________
"When you're up to your ass in alligators, it's hard to remember that you set out to drain the swamp" -- HST