One dares call it treason
Because the American people elected Donald Trump as their president, they are the enemy of the Deep State. If you are an enemy of the American people, you are an enemy of the United States. The Constitution, in Section 3 of Article III, says those who give aid and comfort to the enemies of this country are traitors to it.
President Trump is an existential threat to the entrenched ruling class. The Deep State is a part of that class, and it attacks the president on their behalf. Any and all means are justified in attacking him and in defending their power. Their power is the center of the existence of the ruling class, their most precious possession.
Trump threatens it all, and all of them. So when Adam Schiff mockingly impersonates the president’s call to Ukraine, making it seem like a threatening call from a mob boss, he is giving aid and comfort to the Deep State, the enemy of the people and the enemy of the United States.
Broadly speaking, you’re damn right that’s treason.