President Bush (search) mocked John Kerry's (search) credentials to be commander in chief Wednesday, saying the way to bring U.S. troops home from Iraq "is not to wilt or waver or send mixed signals to the enemy."

Answering a question about the draft at a forum with voters in West Palm Beach, Fla., Kerry said, "If George Bush were to be re-elected, given the way he has gone about this war and given his avoidance of responsibility in North Korea and Iran and other places, is it possible? I can't tell you."

Bush, trying to show a leadership contrast with his Democratic opponent, said on a campaign trip to battleground Pennsylvania: "I'm driven by my desire to protect the American people. I'll be steadfast in my resolve to do everything I can to make you secure."

Less than six weeks before the election, Iraq is increasing in prominence as a campaign issue, thrust to center stage by spreading violence, kidnappings, beheadings and the deaths of more than 1,000 U.S. troops. With Americans divided about the war, Bush is trying to keep voters focused on what he says are Kerry's conflicting statements rather than the daily bombings and bloodshed.

Back in Washington, Vice President Dick Cheney (search) went before TV cameras on Capitol Hill to say Kerry's statements on Iraq and the war on terror showed "someone who lacks the resolve, the determination and the conviction to prevail in this conflict."

In that same vein, the Bush campaign put out a new television advertisement ridiculing Kerry on Iraq and other issues. It shows Kerry windsurfing left and right and says his positions shift "whichever way the wind blows."

The Democrats struck back with their own ad that says: "In the face of the Iraq quagmire, George Bush's answer is to run a juvenile and tasteless attack ad."

Kerry accuses Bush of creating a major crisis in Iraq with no prospect of an end. A number of U.S. troops have had their assignments extended because of the war, but Defense Secretary Donald H. Rumsfeld (search) and other Pentagon officials have said repeatedly that reviving the draft would be neither necessary nor desirable. The Bush campaign called Kerry's comment irresponsible.

Bush campaigned Thursday in the suburbs of Philadelphia and Pittsburgh. It was his 37th visit to Pennsylvania, his top target in the presidential sweepstakes with 21 of the 270 electoral votes needed to win. Four years ago Bush lost Pennsylvania to Democrat Al Gore but polls show the race this year is close.

In between speeches, Bush was taking a helicopter tour of Allegheny County, where the remnants of Hurricane Ivan caused flooding that damaged or destroyed thousands of homes, businesses and public buildings.

On Iraq, Bush will meet at the White House on Thursday with Ayad Allawi, the prime minister of Iraq's interim government who has said the terrorists are being defeated. Bush cited Allawi as a witness to the wisdom of U.S. policy.

"These are critical times and I'm glad the prime minister is here to reinforce the strategy we have in place," Bush said. He said more Iraqis have electricity now than under Saddam Hussein (search) and that more children are going to school and getting immunizations.

Criticizing Kerry, Bush said that "the way to prevail, the way toward successful conclusion that we all want, the way to secure Iraq and bring our troops home as quickly as possible is not to wilt or waver or send mixed signals to the enemy."

"My opponent is sending mixed signals," the president said. "He has had many different positions on Iraq."

Bush has linked Iraq to the more politically popular war against terror, and he suggested that Kerry was too wobbly to keep Americans safe.

"You cannot lead the war against terror if you wilt or waver when things get tough," the president said.

Kerry, his voice scratchy from a cold, said in Florida that Bush was divorced from realities in Iraq and ignoring the manhunt for terrorists in Afghanistan. "Usama bin Forgotten," Kerry said, referring to the Al Qaeda leader, still missing three years after the Sept. 11, 2001, attacks.

Besides Iraq, Kerry focused on Social Security while campaigning in Florida.

His voice scratchy and breaking from a cold, Kerry said the president's proposal to give workers partly private Social Security accounts would end up hurting senior citizens.

"He's driving seniors right out of the middle class," Kerry said in a battleground state rich with voters keenly watching the candidates talk about two pillars of retirement, Social Security and Medicare.

"I will never privatize Social Security, ever," Kerry said, repeating promises not to raise the retirement age or cut benefits.

Kerry's two-day swing through Florida, which began Tuesday, followed deadly hurricanes that nearly halted polling and politicking in the state. Bush made his third campaign-season trip to the state this week to assess damage caused by Hurricane Ivan.