President Bush and leading congressional Democrats lobbed angry charges at each other Friday in an increasingly personal battle over the origins of the Iraq war.

"It is deeply irresponsible to rewrite the history of how that war began," Bush said as he used a Veterans Day address here to lash out at critics. "These baseless attacks send the wrong signal to our troops and to an enemy that is questioning America's will." Democrats retaliated with a barrage of statements accusing the president of skewing the facts, just as they maintain he did in the run-up to the invasion of March 2003.

Although the two sides have long skirmished over the war, the sharp tenor Friday resembled an election-year campaign more than a policy disagreement. In a rare move, Bush in his speech took a direct swipe at last year's opponent, Sen. John F. Kerry (D-Mass.), while the White House issued an unusual campaign-style memo attacking Sen. Edward M. Kennedy (D-Mass.). Republican National Committee Chairman Ken Mehlman followed with a speech blistering 10 Democrats for "political doublespeak."

From their campaign-style war rooms, the Democrats and allied liberal interest groups churned out "fact sheets" dissecting Bush's comments and comparing them with past statements and investigation findings in an effort to undercut his arguments. Kerry accused Bush of "playing the politics of fear and smear on Veterans Day."

The fierce back-and-forth underscored how central Iraq has become in the political environment leading into next year's mid-term congressional elections. After a succession of setbacks for Bush, including slow hurricane relief and a failed Supreme Court nomination, his public standing in opinion polls has tumbled to the lowest level of his presidency.

Anxious White House advisers believe that although other bad news will fade, Iraq remains the most significant long-term threat to the president's political fortunes. Without more tangible signs of progress in the coming months, they fear Bush could find it enormously difficult to reassert his leadership of the country and steer his party through next year's elections.

The latest Washington Post-ABC News poll found that 64 percent of Americans disapprove of how Bush is handling the war and 60 percent believe it was not worth fighting -- in both cases, the worst numbers for the president since the invasion. The perjury indictment of I. Lewis "Scooter" Libby, who resigned as chief of staff to Vice President Cheney, has revived the issue of the administration's truthfulness in building the case for war, and nearly 3 in 5 voters in the Post-ABC poll do not consider Bush honest.

Bush's speech at an Army depot here was intended to address that and turn the tables. Some critics, he complained, "are now claiming we manipulated the intelligence and misled the American people about why we went to war."

The president said that "it's legitimate to criticize my decision or the conduct of the war" but added that "the stakes in the global war on terror are too high and the national interest is too important for politicians to throw out false charges." He said the troops in Iraq deserve to know "that their elected leaders who voted to send them to war continue to stand behind them."

Taking aim at Kerry, who recently announced his support for a phased withdrawal of troops from Iraq, Bush quoted the senator's statement in voting in 2002 for a congressional resolution authorizing the use of force against Saddam Hussein. At the time, Bush noted, Kerry said that "a deadly arsenal of weapons of mass destruction in his hands is a threat and a grave threat to our country." Bush added that other Democrats "who had access to the same intelligence" voted for the resolution.

Kerry later fired back. "This administration misled a nation into war by cherry-picking intelligence and stretching the truth beyond recognition," he said. "That's why Scooter Libby has been indicted."

Senate Minority Leader Harry M. Reid (D-Nev.) said Bush had "resorted to his old playbook of discredited rhetoric" and was "attacking those patriotic Americans who have raised serious questions about the case the Bush administration made to take our country to war."

And Kennedy, who voted against the war resolution, said: "It is deeply regrettable that the president is using Veterans Day as a campaign-like attempt to rebuild his own credibility by tearing down those who seek the truth about the clear manipulation of intelligence in the run-up to the Iraq war."

The exchange of fire heated up as the day wore on. White House press secretary Scott McClellan said it was "regrettable that Senator Kennedy has found more time to say negative things about President Bush than he ever did about Saddam Hussein" and added: "If America were to follow Senator Kennedy's foreign policy, Saddam Hussein would not only still be in power, he would be oppressing and occupying Kuwait."

And Mehlman, addressing a GOP dinner in Fort Wayne, Ind., mocked Democratic calls for further investigation into the handling of intelligence before the war. "Maybe this investigation will reveal that they were brainwashed," he said, according to prepared remarks released by the RNC. "Or that, like John Kerry, they were for the war before they were against it for short-term political gain."

Party strategists said neither side can afford to let the other define how the war began. "We cannot allow a mythology to develop that somehow it was inappropriate to be frightened" of Hussein, former House speaker Newt Gingrich (R-Ga.) said in an interview. "The president absolutely should take on what I would describe as the surrender wing of American foreign policy."

Jim Jordan, a former adviser to Kerry, said Bush's speech reflected weakness. "It was driven by a petulance and frustration, and it had the tone of a president with an approval rating of 35 percent," he said. "He's sounding less statesmanlike when he needs to seem more."

In flying to Pennsylvania, Bush chose a battleground state in next year's election. Standing before a warehouse full of current and former troops, he spoke under a banner that read "Strategy for Victory" and next to a sand-colored Humvee and a 59,000-pound array of satellite and radar dishes.

The crowd cheered him exuberantly, especially when he embraced a constitutional amendment to ban the desecration of the American flag -- a proposal he has supported for years but almost never mentions in speeches. At another point, as he denounced terrorists, someone in the audience yelled out, "Give 'em hell, George."

Sen. Arlen Specter (Pa.) was on hand, but notably absent was fellow Republican Sen. Rick Santorum (Pa.), who trails badly in his bid for reelection next year. His press secretary, Robert Traynham, said the senator was speaking at a long-scheduled American Legion luncheon in Philadelphia and could not be in two places at one time. Jay Reiff, campaign manager for Democratic challenger Robert Casey Jr., said Santorum "is clearly trying to distance himself from an unpopular president and an unpopular agenda."

Baker reported from Washington.

President Bush meets with service members after giving a Veterans Day address in Tobyhanna, Pa. Bush forcefully attacked war critics, saying they are trying to rewrite history.