The battle of the airwaves has definitely hit Wisconsin; after the first round of back-and-forth in TV ads over why-no-debate in the state whose primary is Tuesday, the campaign of Senator Hillary Rodham Clinton has taken a decidedly negative, may we say spine-chilling swing, in this next round. As has been asked allaround, will this shift toward a far more direct attack mode undercut the possible momentum gained by Senator Barack Obama in his spate of new wins this month, or will it turn off voters in a state where issues are issues, thoughtful and pronounced? Mrs. Clinton’s new TV spot accuses Obama of putting out “false attack ads” in response to her original TV spot that criticized him for not agreeing to debate her in Milwaukee. Mr. Obama’s ad, put out Thursday, said that the 18 past debates and two upcoming forums in Ohio and Texas were enough. The new ad not only calls out Mr. Obama for refusing the debate invitation, but it also reiterates her contention that his health care plan would leave 15 million Americans without coverage.