Also because the left always overreaches, as evil always does. People have perfectly good BS detectors. The problem is they see ALL politicians as corrupt hacks and apply a certain moral equivalency. The logical fallacy of the truth falling somewhere in the middle.
Trouble is I'm not sure they're wrong about the repubicans.
There are bozos in every aspect of life, and the Republican Party is no exception. However, the GOP is, in aggregate form, way way way better than the Dems! Also, we (the GOP) have a noble history. The Dems’ history is as the party of slavery, segregation, Jim Crow, the KKK, and opposition to every piece of civil rights legislation the GOP attempted to pass. Then, just as they were getting that out of their system, they became the nothing more than the American arm of the international marxist-leninist left. There is no contest and no comparison between the two. Sinistrum delenda est.