...they are attempting to overthrow a Democratically-elected President using non-democratic means, and all of is based on lies.
This is most definitely not "treason". They are attempting to remove a criminal President, using the impeachment provisions of the Constitution. This is the Constitutional removal of a criminal President who should never have been allowed to run for President because of his history and temperment.
"Treason" is defined as aiding and abetting the enemy in the time of war declared by Congress. Unless Democrats are aiding and abetting the Talaban in Afghanistan, they are not committing treason.