Richland Center, Wis. ? With a week until the election, Democratic nominee John Kerry accused President Bush on Tuesday of hiding embarrassments in Iraq, and Bush chastised Kerry for grasping at headlines instead of building a coherent proposal.

Bush, appealing to what he called “discerning Democrats” as he rumbled through rural Wisconsin on the last of 20 campaign bus tours, said Kerry projects “weakness and inaction,” forsaking his party’s tradition of national strength. “My opponent has no plan, no vision — just a long list of complaints,” Bush said in the Mississippi River town of Dubuque, Iowa. “But a Monday-morning quarterback has never won any game.”

Kerry, also in Wisconsin, accused Bush for a second day of failing to secure stockpiles of explosives in postwar Iraq and painted a grim and ominous portrait of the Bush presidency. “These explosives … could produce bombs powerful enough to demolish entire buildings, blow up airplanes, destroy tanks and kill our troops,” Kerry said at a rally at the University of Wisconsin at Green Bay.

With Tuesday’s clash in Wisconsin — one of nearly a dozen states where the electoral outcome is unclear — the candidates approached the last seven days of the campaign with ever-harsher attacks even as their aides planned to close on a positive note. Polls show no clear advantage or momentum for either side, magnifying the importance of each campaign stop and each news cycle.

In a new Kerry commercial airing in five states and in his speeches, the Democrat continued to make a case that the disappearance of nearly 400 tons of conventional explosives in Iraq is fresh evidence that Bush had botched the war and now was covering up his miscalculations. And Bush remained determined not to respond to the Democratic charge. Asked by a reporter about who was responsible for the missing munitions, Bush, on a visit to a dairy barn in Viola, Wis., did not say anything but simply glared, journalists with him said.

The White House says that the explosives’ disappearance, first reported by the New York Times and CBS News and confirmed Monday by the International Atomic Energy Agency, has been exaggerated by what they describe as the liberal media. Bush’s campaign worked aggressively to discredit the report, reflecting the nervousness of aides about a race over which they now have little control and worry could tip on any given story.

Kerry visited three states Tuesday he is nervous about losing: Wisconsin, Nevada and New Mexico. He is planning a sleepless weekend to hit as many cities as possible in the final 72 hours.

Bush’s aides said they would release his closing ad today, featuring an emotional clip from the president’s speech to the Republican National Convention, as part of an effort to lure back voters who supported Bush after the attacks of Sept. 11, 2001, but have since turned on him.