The Monday midday headlines at StarTribune.com made for a disconcerting juxtaposition. At the top: The Dow Jones industrial average had plummeted more than 500 points. Down the page: "Palin expands criticism of Obama to include Rev. [Jeremiah] Wright."

Voters who might have been looking to the presidential campaigns for a reasoned reaction to the economic news were treated, instead, to a reminder that Barack Obama used to have a pastor with nutty ideas. Who knows? Perhaps some of them welcomed the distraction.

Similarly, GOP vice presidential candidate Sarah Palin has been calling attention to the Democratic presidential nominee's support by a Chicago education professor who was an antiwar radical 40 years ago — when Obama was a child. "Pal­ling around with terrorists," she called it over the weekend.

The Obama campaign threatened to return fire — which, when mentioned on national television, is the same thing as actually firing — by pulling a brittle skeleton out of John McCain's closet. Be careful, Obama surrogates warned, or we'll bring up the 20-year-old "Keating Five" scandal, in which McCain and four other senators were accused of steering federal regulators away from failing Lincoln Savings & Loan Association until its failure had cost customers and taxpayers billions of dollars. McCain was ultimately rapped by the Senate Ethics Committee for "poor judgment" but no wrongdoing in the matter.

The Obama campaign threatened to return fire — which, when mentioned on national television, is the same thing as actually firing — by pulling a brittle skeleton out of John McCain's closet. Be careful, Obama surrogates warned, or we'll bring up the 20-year-old "Keating Five" scandal, in which McCain and four other senators were accused of steering federal regulators away from failing Lincoln Savings & Loan Association until its failure had cost customers and taxpayers billions of dollars. McCain was ultimately rapped by the Senate Ethics Committee for "poor judgment" but no wrongdoing in the matter. If these Monday headlines are a preview of the next month of presidential politicking, some Americans might be wishing they could skip the movie. That thinking might be especially prevalent in Minnesota. This state's voters have shown repeatedly that they don't respond positively to negative campaigns.

The latest Star Tribune Minnesota Poll, released Saturday, offers fresh evidence that in this state, perhaps more than others, "going negative" can backfire. That explanation was offered for the DFL challenger Al Franken's surge into the lead in the three-way race for the U.S. Senate seat held by Republican Norm Coleman. Conducted last Tuesday through Thursday, the poll found that Coleman's approval rating had dropped during the weeks when his campaign and its national Republican allies dunned Minnesotans with broadcast messages berating Franken on personal grounds.

Coleman ought to know well the risk he runs with that strategy. Ten years ago, Jesse Ventura's upset gubernatorial victory was chalked up in part to the advertising beating Republican Coleman and DFLer Skip Humphrey inflicted on each other and, unwittingly, themselves. Voters preferred the third-party guy who wasn't in the crossfire. It's likely no coincidence that this year, the Independence Party's Dean Barkley has been climbing in the polls. The Minnesota Poll found that 56 percent of respondents considered ads from the Coleman campaign criticizing Franken to be "mostly unfair personal attacks." Forty-two percent said the same about Franken ads that criticized Coleman.

The Senate race in Minnesota two years ago offers more evidence of this state's disdain for attack-ad politics. Amy Klobuchar won by eschewing negative advertising; her GOP opponent, Mark Kennedy, ran a highly negative campaign but gained no ground in the polls.

Minnesotans aren't political Pollyannas. This year especially, they deserve no-holds-barred discussion of the decisions that will confront the nation in the next six years. They want the public records of incumbents held up to scrutiny. But they rightfully resent over-the-top attempts by candidates to portray their opponents as deficient in character or guilty by association. In this state, politicians who are tempted to try to discredit their opponents, Swift Boat style, should be advised that here, those boats often don't float.