The answer is none.
They already control the voting process, why would they need anything else?
Liberals also control (own) the media and the educational ‘system’. So now they can (and routinely, do) deploy at will, the unlimited power and unlimited resources of the US government.....
It's the perfect storm! And they hate Trump because he sees this and has been one of the very few politicians courageous and articulate enough to continually and categorically address this