It doesn’t mean much though since Bundy and Baumeister were republicans. I guess with Gacy is that he has connections to other serial killers and pedophiles who were part of a larger network, but not much tying political figures to it. Baumeister was very wealthy and a businessowner so he likely had some political connections.
He was pretty politically active actually, locally in the democratic party. But I wouldn't say he is the only democrat who loves systematic mass murder