In 1986, conservatives in California were saddled with a horrible choice for US Senate as Democrat Alan Cranston, an old hard-core lefty who was running for re-election, faced off against Rep. Ed Zschau (rhymes--appropriately--with Mao), a Vito Marcantonio Republican.
Some conservatives voted for Zschau because Cranston was so bad, and they wanted the GOP to keep control of the Senate, some voted for Cranston because they knew he would only serve one more term, and they feared that Zschau, being young, would be there forever. I wound up going third party.
I had heard of Vito Marcantonio because of Richard Nixon (he had used in one of his early campaigns how often his opponent had voted with Marcantonio), but I had not realized that Marcantonio was originally a Republican.