Today Ann Arbor voters choose their next state senator and state representative, two city seats on the county commission, and three city council members. They’ll also decide the Democratic mayoral primary between five-term incumbent John Hieftje and publisher Pat Lesko.

In July, the Ann Arbor Observer called this a “once-in-a-generation political slugfest,” and it’s ending up as contentious and personal as it began. Hieftje touts his record as among the best in Michigan, defends the city administration as competent and city council as working well together in hard times – and blasts Lesko as a distorter of the truth and a misinformed critic of the city’s budget.

While insisting it’s nothing personal, Lesko blasts the mayor, the administration, and most of the city council. She describes the city as mismanaged and wasteful, speaking both in her own name and on her formerly anonymous blog, – where she famously said she she’d vote for Satan before she’d vote for Hieftje again. Hieftje responds with a vigorous defense of his record, and pointed questions about Lesko’s understanding of Ann Arbor’s government.

It’s a stark choice and a defining moment for the city. But who will win?

According to Lesko, it will be Lesko.

“We recently did a random poll of 100 registered voters in Ann Arbor (by phone) and the results of the poll were:

“60 percent Lesko

“40 percent Hieftje,”

she emailed in late July.

“I try not to make predictions,” Hieftje says–then notes that “this is an especially tough year for incumbents everywhere. It is so easy to blame whoever is in office for cuts that have had to be made, when as those of us doing the work know, this has been a hard decade to be in public service. For this reason I expect the totals for incumbents will be down.” But because he doesn’t make predictions, he wouldn’t guess how far down.

“The outcome will depend on who turns out to vote,” says a Lesko ally who asked to remain anonymous. “Going door to door, I’ve encountered considerable anti-incumbent sentiment. On-line, I’ve encountered considerable personal dislike of Ms. Lesko. One of these groups will be more motivated and actually show up to vote. That, in turn, will determine the results. Should the anti-incumbent voters turn out, I think Lesko would prevail 55 percent to 45 percent.”

If that happens, it will be the political upset of the century. Hieftje won his past two mayoral primaries by landslides–68-32 percent against driver’s ed instructor Tom Wall in 2008 and 70-30 against city councilwoman Wendy Woods in 2006. That leads one City Hall insider to call 30 percent the “name on the ballot” vote: a core anti-incumbent sentiment that can be tapped by any challenger. To reach her poll’s prediction, Lesko would need to double that.