“The prosecutor has to find a criminal statute that fits the offense.”
Treason?, Sedition?
The issue with treason is that it dpends on helping an enemy country, not an enemy political party. Generally, treason depends on being in a state of war, and having a traitor.
The issue with sedition is that all the sedition offenses require the actor to perform or advocate acts of violence. Overthrow of government by non-violent subterfuge is not sedition under the current criminal statute.
18 USC Chapter 115 - TREASON, SEDITION, AND SUBVERSIVE ACTIVITIES
There is only a handful of criminal statutes in that Chapter. Take a moment to read all of them you think might apply.