It's an old trick. Reminds me of the time when a Klansman endorsed Goldwater, despite the fact that there was a genuine pro-Segregationist party being run in the same race, and the Klan was founded by (and was still staffed at the time by) Democrats.

Another trick LBJ pulled was having something like 1,000 psychologists sign onto a document that declared Goldwater to be mentally insane, all without anyone diagnosing him, without seeing him, and in many cases not knowing what they were signing. That's what lead to the APA creating the "Goldwater Rule"