George W. Bush launched a tough new ad Tuesday accusing Al Gore of ''bending the truth,'' setting the stage for a bitter climax to their closely fought presidential campaign. Gore said Americans need a president who will fight for them ''and has the experience to do so.''
Gore advisers jumped on Bush for challenging the vice president's character after promising to run a positive campaign. Even so, the Gore team considered a last-minute ad questioning whether the Texas Republican was ready to be president.
A week before Election Day, each candidate struggled to pull away from the other - while a budget showdown in Washington and scores of close congressional races competed for voters' attention.
Ralph Nader, the presidential race's third-party wild card, upped the ante with a biting satire ad that cast the Bush-Gore race as a choice between ''the lesser of two evils.''
The negative turn on all fronts was further proof that neither major-party campaign was confident enough of victory to close the race in traditional fashion with high-minded positive ads. Analysts said both candidates could face a backlash - with little time to recover.
A number of Republicans privately said they were surprised that Bush would take the risk, suggesting his move belies the apparent confidence he and his troops are careful to keep on display.
The candidates chased each other across California and Oregon, two states Gore hoped long ago to lock up. Bush could win Oregon and its seven electoral votes, but California, the election's biggest prize at 54 electoral votes, is still a longshot.
In Oregon, Gore cast himself as the dragon-slaying populist in hopes of drawing Nader supporters back into the Democratic fold.
''You need someone who will fight for you and win and has the experience to do so,'' Gore said. The line came out of polls that show many voters still question Bush's credentials.
Bush has criticized Gore for playing ''class warfare'' in his tax-cut arguments. Gore turned that against the Republican on Tuesday, too, saying: ''What he is actually proposing is a massive redistribution of wealth from the middle-class to the wealthiest few. It is, in fact, a form of class warfare on behalf of billionaires.''
Bush stuck to the strategy of telling voters he is a sunny optimist, a champion of bipartisanship. ''I can't think of a better way to end a campaign in an important state than to come to a place that is founded not on politics but on love,'' he said at a Christian relief agency in San Jose, Calif.
His new ad says Gore is ''bending the truth'' and talking ''nonsense'' about Bush's Social Security plan. It shows a video clip of Gore saying he had never said anything that was untrue.
The ad ends with the word ''Really?'' driving home Bush's point: Gore can't be trusted.
Strategist Karl Rove said Bush needed a blanket inoculation against Gore, who has tried and abandoned several lines of attack in recent days - from the condition of schools and nursing homes in Texas to Bush's lack of experience.
With polls showing Bush slightly ahead or the race essentially even, Rove said, ''It's close enough that we can't let it dissipate, and the way to make sure it doesn't dissipate is to counterpunch.''
Gore allies hoped to make Bush pay a price for the character ad.
''How can Bush bring civility to Washington when he can't even bring civility to his own faltering campaign?'' said Gore deputy campaign manager Mark Fabiani, who also called the GOP candidate a liar and hypocrite.
Republicans offered cautious support of Bush's ad, which will be rotated in an $11 million campaign with a more positive spot about his governing philosophy. Even that high-toned ad is called, not coincidentally, ''Trust.''
''Making Gore and his lack of trustworthiness a dominate issue is a strong way to close the campaign for Bush,'' said Scott Reed, who managed Bob Dole's 1996 campaign.
But he said the fact that Bush took this step shows ''that Gore's scare tactics are beginning to draw some blood, especially in states like Florida.''
Both candidates shied away from the budget battle in Washington the day after President Clinton vetoed a $3,800 pay raise for members of Congress and set off a firestorm of protest from GOP lawmakers.
Like Gore with Clinton, the Texan has tried to distance himself from the GOP-led Congress which is unpopular with many swing voters. Spokeswoman Karen Hughes said Bush could avoid ''this exact kind of annual confrontation'' if elected president.
Gore's situation is more complicated. Aides have considered for days having the vice president join Clinton in denouncing the Republican position. But they are treading carefully out of fear that Clinton would overshadow the vice president and undermine Gore's efforts to show that he is running as his own man.
Gore also has gone to great lengths this campaign to keep his distance from Clinton, whose impeachment is still a sore spot with many swing voters.
Gore doesn't necessarily share the same goal as House Democrats. They hope to trigger a loud, chaotic battle with Republicans as they seek to shake up the political environment in advance of the Nov. 7 elections. A fight energizes core Democrats, who could make the difference in the battle to overturn the GOP's razor-thin advantage in the House.