There’s a reason Rick Santorum was robo-calling Michigan Democrats yesterday to get them to vote for him over favorite son Mitt Romney. It could work. And those mischievous voters — ticked off at that state’s governor or at Romney himself — could propel him to victory the same way they did Sen. John McCain (R-Ariz.) in 2000. After all, in all of the latest polls out of Michigan, Santorum and Romney are in a statistical tie.

The Wolverine State’s reputation for tripping up front-runners is well known. In a Feb. 23, 2000, post for PBS’s Online Newshour, Carol Weissert, associate professor of political science at Michigan State University, wrote that Michigan has “a record of bipartisan orneriness that dates back to 1912 when voters supported Theodore Roosevelt as a Bull Moose candidate.” This is because the state’s primary is basically an open one. According to the New York Times’s Michael Shear, writing for the Caucus blog, “Voting booths will be open only to Republicans, but party rules allow anyone to declare himself a Republican on the spot — temporarily — and then vote.”

That Michigan orneriness was dramatically on display during the Republican primary in 2000. Then-Texas Gov. George W. Bush, the moneyed, establishment front-runner, was shellacked by McCain, 51 percent to 43 percent, thanks to heavy turnout by independents and Democrats.

Weissert noted then that Bush “garnered the support of most of the state’s Republicans.” One exit poll showed him snagged 58 percent of that vote compared with 37 percent for McCain. But exit polls also showed that independents and Democrats accounted for 51 percent to 53 percent of primary voters. “According to Detroit News exit polls,” Weissert wrote, “McCain garnered support from 66 percent of the Independents and 86 percent of the Democrats.”

What motivated Democrats to come out for McCain? Anger at then-Michigan Gov. John Engler (R), who was running Bush’s campaign in the state. Folks in Detroit had a particularly jaundiced view of him because they thought his policies hurt that city. University of Detroit analyst Stephen Manning told the New York Daily News in February 2000, “Engler is much despised in Detroit.. . . Bush has to be worried about the ‘I hate Engler’ vote.” And to prove the point, the News quoted Janet Burgess, who said, “I just want to tick off Engler.” Burgess was described by the newspaper as “a 52, a bedrock Democrat and African-American woman from Detroit, [who] happily admitted that she would vote for McCain and then switch back to Al Gore in the fall.”

Fast-forward to today. The target of such Democratic animus could be Romney supporter Gov. Rick Snyder (R). Even though the state enjoys its first surplus in a decade, many believe he got the extra budgetary cash in part by sticking it to the middle class and working poor. But the target could also be Romney himself.

The former Massachusetts governor was born and raised in Michigan. His father ran a car company there and was the state’s thrice-elected governor. But his vocal opposition to the popular auto bailout could be the spark that fires up Democratic turnout today. As the NBC News-Marist poll made plain last week, while 50 percent of likely Republican primary voters thought the auto bailout was a “bad idea,” 63 percent of registered voters across the state thought it was a “good idea.” And 58 percent of registered voters across the state say President Obama deserves “a great deal/a good amount” of credit for the recovery of the auto industry.

A Democrat has won Michigan every presidential election since 1992. Obama won it by 16 points against McCain in 2008. If Democrats wanted to send a message to Republicans in general and Romney in particular, today’s the day they could be heard loud and clear.