Sedition, not treason. He's attempting to usurp the legal government process through extralegal reasons and replace our current form of government with a different one. Sedition wasn't covered in the constitution, but the Alien and Sedition acts were passed during the Adams administration in the leadup to the War of 1812 (our real war of independence). However, the Alien and Sedition acts were passed before the Supreme Court pulled the power of Judicial Review out of its ass, and it's likely they wouldn't surivive a modern test for constitutionality. Doubt we'll see any Attorney General bring charges under those acts, blatantly unconstitutional laws tend not to work well against white criminals with money to defend themselves.
Treason would be acting with a foreign agent to overthrow the government. For example, one could commit treason by supplying classified documents (that were stolen from the White House and improperly stored in a bathroom) containing information about identities of field agents to agents of foreign powers, in exchange for monetary and/or political gain. Even though most people would consider such actions to be treasonous, treason carries the death penalty so it's hard to get it to stick. Usually folk who do that sort of thing get tried under the Espionage Acts. See Manning and Winter, imprisoned for espionage; vs the Rosenbergs, executed for treason.
If we're talking criminal action, I'd think Rudy should be tried under the Alien and Sedition acts, but more likely various state election interference statutes. Someone who will remain nameless has clearly committed treason & espionage, though I doubt we'll ever see his Orangeness meet the same fate as either Manning/Winter or the Rosenbergs, despite his causing significantly more damage to our nation.
Mozilla about to lose funding from Google antitrust consequences :(