The candidates traded biting accusations over the war in Iraq as early Florida voting produced scattered complaints that stirred memories of the state's chaotic 2000 recount.
On a day of strikingly personal campaign rhetoric, Mr. Bush on Monday said his Democratic challenger stands for "protest and defeatism" in Iraq. He added that Kerry would lead the nation toward "a major defeat in the war on terror."
The four-term Massachusetts senator accused the president of "arrogant boasting" to hide bitter truths about a war waged on his command. He cited a published report saying the top general in Iraq had warned Pentagon officials last winter about a shortage of supplies.
If anything, Democratic running mate John Edwards was harsher. Mr. Bush is trying to "con the American people into believing that he is the only one who can fight and win the war on terrorism," said the North Carolina senator.
Little more than two weeks before Election Day, the national polls showed a tight race. The two rivals are tied statistically in some and Bush holds a slender advantage in others. Yet several recent surveys show the president beneath 50 percent support, often a late-campaign sign of difficulty for any incumbent.
In a new, Mr. Bush leads Kerry 47-45 among likely voters, with Ralph Nader taking 2 percent. The lead is within the poll's margin of error.
An ABC News tracking poll based on interviews conducted Thursday through Sunday has Bush with a 50-47 lead among likely voters. The survey of 1,544 likely voters has a 2.5-point margin of error. A Washington Post tracking poll of 1,656 likely voters arrives at identical results: Mr. Bush leading 50-47 percent, within a 3-point margin of error. But the Post has Kerry ahead 50-46 percent in 13 battleground states.
But a Quinnipiac University poll of New Jersey, a state Kerry is counting on, shows him with a slim 49-45 percent lead over the president, who visited the Garden State on Monday.
Earlier this week, a CNN/USA Today/Gallup poll of likely voters had Mr. Bush up 52-44 percent; among registered voters, Mr. Bush's lead fell to 49-46 percent. A Reuters/Zogby poll of 1,211 likely voters had the race a 45-45 tie.
Aides to both candidates claimed to possess private polls showing their man ahead in the dozen battleground states that will determine the outcome of the election.
Florida was prominent among them. There, the first difficulties surfaced soon after early voting opened in the state whose recount reached the Supreme Court four years ago before propelling Mr. Bush to the White House.
"This is not a good start," said Democratic State Rep. Shelley Vana, adding that the paper ballot she received in a Palm Beach County, Florida, polling place was missing a page.
There were a few computer-related problems elsewhere across the state, but no early reports of difficulties with ATM-like touch-screen voting machines introduced since the troubled 2000 election. "It tells you exactly what to do. It's idiot-proof," said Robin Punches, voting in Palm Beach County.
Kerry spent his day in Florida, urging supporters to vote early at each stop. Mr. Bush had appearances in the state Monday night and Tuesday, part of an effort to motivate his backers to cast early ballots as well.
On Tuesday, Kerry will be in the three top electoral vote prizes that analysts say are still up for grabs — Florida, Pennsylvania and Ohio. Those three states account for 68 electoral votes, more than a quarter of the 270 needed to be elected.
Mr. Bush put the powers of incumbency on display during the day, signing legislation at the White House to finance the Department of Homeland Security before flying off for a speech on terrorism in New Jersey.
Along the way, he accused his rival of "shameless scare tactics." In an Associated Press interview aboard Air Force One, Bush said Kerry is "trying to scare our seniors" with false charges of a secret Republican plan to privatize Social Security.
He also faulted Kerry for telling younger Americans there will be a return to the military draft — an option Bush has repeatedly and emphatically ruled out.
The president's speech in Marlton, N.J. was an indictment of Kerry's position on the war in Iraq, delivered in a state that felt firsthand the loss of life at the World Trade Center on Sept. 11, 2001, and last voted for a Republican presidential candidate in 1988.
"The senator from Massachusetts has now flip-flopped his way to a dangerous position ... a strategy of retreat," Mr. Bush said. "He has talked about artificial timetables to pull our troops out of Iraq. He has sent the signal that America's overriding goal in Iraq would be to leave, even if the job is not done."
He added that while "America does the hard work of fighting terror and spreading freedom, he has chosen the easy path of protest and defeatism."
Kerry aide Michael McCurry called Mr. Bush's speech "arguably his strongest negative attack to date," and said the Democratic senator was "going to be rebutting that very aggressively" in the next two or three days.
Kerry rebutted by citing Gen. Ricardo Sanchez, the former top general of U.S. forces in Iraq. Referring to a report in The Washington Post, Kerry said that the day after Sanchez warned Pentagon superiors about supply problems, "George Bush went out and told the American people our troops were properly equipped."
"Despite the president's arrogant boasting that he has done everything right in Iraq and that he's made no mistakes, the truth is beginning to catch up with him," Kerry said. "And it's a bitter truth, my friends."