It’s also possible they think/know that even with voter fraud they cannot beat Trump, but as long as they create enough chaos and confusion, they will be able to declare the election invalid (again) and refuse to accept it (again) and position themselves as the resistance (again). See, they know they look like assholes when they do this so they have to frame it as patriotic. That was one of the major reasons for Russian Collusion. One, to cover up for Spygate, and two, to give the media an excuse not to show President Trump the basic respect and courtesy all Presidents have gotten.