Spoiler candidates backed by opposition

How many times has this actually happened? I have been hearing theories that conservatives are secretly backing Jill Stein, hoping to get Trump elected. I don’t usually believe conspiracy theories, but something similar happened in Maine’s last governor’s race. http://m.dailykos.com/story/2014/10/28/1339761/-Republicans-try-to-undercut-Maine-Democrats-by-boosting-independent-Eliot-Cuter
Mr. Cutler was a liberal independent, and was backed by Republicans in order to split the liberal vote and keep Lepage in office. It worked.
Are there any other elections where there is proof of something like This happening?

There’s certainly a lot of speculation that the Republicans helped Nader in both 2000 and 2004. I’m sure they would be happy to help Stein, but Stein has proved herself to be such a joke that the only voters that are voting for her are the ones Clinton would never win anyway.

In the 2012 Missouri Senate race, Claire McCaskill ran a negative campaign ad against Todd Akin in his Republican primary declaring that he was too conservative for Missouri and that voters should reject him in the primary. She did that knowing full well that Republican voters would take that as a cue to vote for him and McCaskill, having secured the general election opponent she wanted in the first place, proceeded to beat the hell out of him.

In these parts we have examples of stalking horse candidatesalmost every election cycle. Someone who happens to have a name very close to that of another candidate will get their name on the ballot, do no campaigning whatsoever, pick up a few dozen or hundred or thousand votes, and disappear immediately after the election.

That kind of shennanigans generally doesn’t go past the primaries, though.

There have been plenty of cases of one party meddling in the primaries of the other party. The most famous being California Governor Davis meddling to squash Riordan so he could face a weaker opponent. That sequence of events led to the recall and the Governator.

I remember here in Illinois, one of the unions backed the libertarian candidate in the election in order to split the Republican vote (it seems like the amount was $50,000, but I can’t remember the seat or the candidate). Does anyone remember which one this was?

Back in 1980, veteran liberal Republican Senator Jacob Javits was defeated for the Republican nomination by Al D’Amato. Javits ran as an Independent, and siphoned off a lot of votes from liberal Democrat Liz Holtzman, allowing D’Amato to win.

MAYBE this was just an ego trip for Javits, but a lot of Democrats suspected that the GOP had promised Javits some kind of reward (ambassadorship to Israel, or something) for staying in the race.