It's easy to be cynical about politics and especially about negative ads.
Minnesotans were bombarded with tens of millions of dollars worth of political ads this year — the vast majority of them intoning in a dark, whispery voice how one candidate or another was so bad you wouldn't leave your kids alone with him.
Given all the money the campaigns spend on polling and focus groups and to produce the ads and purchase the TV time, a reasonable — and depressing — response during the campaign is that if they didn't work, they wouldn't use them.
But it's not always true. Negative ads can occasionally backfire, which may be what happened in the Third Congressional District race in which Democrat Dean Phillips beat U.S. Rep. Erik Paulsen, a Republican.
Zach Rodvold, Phillips' campaign manager, said they saw this in their own internal polling, which was conducted by Greenberg Quinlan Rosner, a widely respected Democratic firm.
A barrage of attacks accused Phillips of not giving his coffee shop employees health insurance when the shop first opened. (Phillips did offer insurance later.)
The ads were effective, insofar as people in the district became aware that Phillips was Paulsen's opponent and that he owned a coffee shop and didn't give his employees health insurance.
The problem with the attack was that the voters didn't expect a coffee shop owner to provide insurance.