The news that Rick Santorum is courting the votes of Democrats to mess with Tuesday's Republican primary in Michigan has raised concerns that "mischief votes" might actually achieve their purpose of keeping the horse race alive. Santorum's campaign acknowledged Monday they were robo-calling Democrats suggesting they vote for him -- and though his campaign wasn't so foolish as to admit that their strategy was to accept votes from the hard left, claiming they're courting Reagan Democrats -- Mitt Romney quickly criticized it as "outrageous and disgusting." Santorum's solicitation of his political antagonists might be a new wrinkle in this endless primary season, but the "mischief vote" is an old trick in open primary states where anyone can vote in any party's race.

With that in mind, we've assembled a brief, recent history of the more notable cross-over voting campaigns to see what Santorum can learn from his forebears. 

The election: Bill Clinton vs. Paul Tsongas vs. Jerry Brown for the Democratic nomination in 1992

The mischief: With an incumbent George H.W. Bush freeing them up, Republicans were able to pay attention to the most interesting race: The Democratic one. When Newt Gingrich accused Mitt Romney of voting for Tsongas in a debate this year, Romney pretty much admitted to it: "I've never voted for a Democrat when there was a Republican on the ballot. And -- and in my state of Massachusetts, you could register as an independent and go vote in (whichever) primary happens to be very interesting. And any chance I got to vote against Bill Clinton or Ted Kennedy, I took." News reports also cited a mischief campaign for Jerry Brown in Wisconsin among Republicans.

What we learned: Mischief campaigns sometimes fail. Rather than heavily influence this contest, the campaign mostly served to set an example for the Democrats, who quickly turned it around on Republicans the next chance they got.

The election: Bob Dole vs. Pat Buchanan for the Republican nomination in 1996.

The mischief: In New Hampshire and Wisconsin, Democrats voted for Buchanan, who came from the far right to challenge the presumed frontrunner and establishment choice Bob Dole. (Sound familiar?) Bill Clinton's incumbency freed up Democrats to vote Republican and in Wisconsin (where the Republican campaign for Jerry Brown remained fresh), Democratic voters overwhelmingly picked Buchanan. As progressive labor leader James Cavanaugh told the Madison based Capital Times, "A lot of Democrats who would never think of voting for Buchanan in November backed him in the primary... Some of those votes were because Buchanan was saying a few good things on the economy -- he's against NAFTA and GATT, he criticizes the corporations. But most of them came from people who know that every vote he gets messes the Republican Party up a little more."

What did we learn: Perhaps the most obvious take-away from these well-publicized mischief campaigns is that their publicity sort of defeats the purpose. If everyone regards Buchanan's win as a Democrat tactic, well, that's not exactly a great endorsement for a candidacy.

The election: Hillary Clinton vs. Barack Obama for the Democratic nomination in 2008

The mischief: While Republicans settled relatively quickly on John McCain, Democrats faced an indecisive, drawn-out contest between Obama and Clinton. Enter Rush Limbaugh who organized "Operation Chaos," a campaign to encourage Republicans to change their party registration and vote for Clinton, who was losing in the delegate count, to further "prolong" the election. Obama blamed his narrow loss in Indiana on Limbaugh's followers. And some reports showed hundreds of thousands in states like Pennsylvania joining the call. 

What did we learn: Rarely do mischief campaigns actually expect to upend a front-runner's candidacy. Most of them mention "prolongment" of a bloody contest as the goal. Limbaugh hoped he might get Clinton all the way to the convention, where he envisioned 1968 style riots. (Delightful, this one.) So perhaps instead of embracing Democrats, Santorum should note the subject of an opposition party's voting campaign rarely comes out victorious, even if he or she ekes out a few primary wins that otherwise would have gone to the front-runner.

The election: Ron Paul vs. several opponents in our very own 2012 race for the Republican nomination.

The mischief: The Washington Examiner's Byron York ran an article complaining that much of Paul's success was coming from non-Republican voters, the classic sign of a mischief campaign. "Paul is doing the best job of getting those people who aren't really Republicans but say they're going to vote in the Republican primary," pollster Andrew Smith told York. The group includes Democrats who want  to "throw a monkey wrench in the campaign by voting for someone who is more philosophically extreme," says Smith. But, he concedes, it also includes libertarians and independents. 

What did we learn: Just because people unaffiliated with a party are voting for a candidate in a primary doesn't mean there's mischief. Sometimes a candidate's quirky platform actually inspires cross-over. People do leave their parties, after all.

That seems to be the sentiment Rick Santorum's campaign had in mind when a spokesperson said their robo-call sought to convert Reagan Democrats, another prominent group that was earnestly swayed by the other party. But surely the campaign has noticed the tactics of decidedly non-Reagan Democrats at the Daily Kos who have encouraged readers to vote Santorum. As we noted, a well-publicized mischief campaign rarely does much to help the assumed beneficiary, so for Santorum to give more attention to an otherwise small movement among liberals to vote for him really only serves to give the Romney campaign a wide-open excuse for any poor performance in Tuesday's contest. What we learn in general: if you're the subject of a mischief campaign, that should inspire concern, not prompt cooperation. Note that none of our examples of recipients mischief votes ever actually won a nomination, let alone a general election, as a result of them. That's because they were selected chiefly because their opponents sized them up as unelectable. Santorum's campaign was likely thinking they'd bang out a win in Michigan with the help of Democrats and then think about the general election when they got there. Based on recent history, you can count us skeptical that they've found a working tactic.