PHILADELPHIA - Sen. John Kerry (news - web sites) cited the Iraq...

PHILADELPHIA - Sen. John Kerry (news - web sites) cited the Iraq (news - web sites) war and a huge cache of missing explosives Monday as proof President Bush (news - web sites) has "failed the test of being commander in chief." The Republican slammed his rival as "consistently and dangerously wrong" on national security matters.

In a race of ever-escalating rhetoric, the president also accused the Democratic challenger of "the worst kind of Monday-morning quarterbacking" on the wars in Afghanistan (news - web sites) and Iraq. But he fell silent on the disappearance of 377 tons of high explosives in Iraq, leaving it to aides to explain.

Public polls in the major battleground states of Pennsylvania, Ohio and Florida were so close that both camps had cause for optimism — and room for doubt. And with only eight days to go, there were signs that the field of competition might be widening.

Democrats fretted about a tight race in Hawaii and made plans to advertise to voters in the state.

Polls showed a tightening race in Arkansas, a state the president won four years ago and the Democrats had virtually given up for lost this time. The president's high command was concerned, as well, about New Hampshire, in Bush's column four years ago, trending Kerry's way in the race's final days.

Long-planned events blended with the unexpected in a campaign already marked by unpredictability.

Former President Clinton (news - web sites) joined Kerry at a noontime rally in Philadelphia that drew tens of thousands. "If this isn't good for my heart, I don't know what is," Clinton said, looking thinner seven weeks after bypass surgery.

Supreme Court officials announced that Chief Justice William H. Rehnquist, 80, is undergoing treatment for thyroid cancer and is expected to return to work next week. The statement served as a reminder that the next president is likely to have more than one appointment to an aging court that is divided on abortion, gay rights and more.

Word of the disappearance of explosives from a military installation in Iraq was like a campaign gift to Kerry, and he quickly put it to use.

Failure to secure the material was "one of the great blunders of Iraq, one of the great blunders of this administration," the four-term Massachusetts senator said in New Hampshire, his first campaign stop of the day.

"Terrorists could use this material to kill our troops, our people, blow up our airplanes and level buildings."

"...The unbelievable blindness, stubbornness, arrogance of this administration to do the basics has now allowed this president to once again fail the test of being the commander in chief," Kerry said.