DOWNINGTOWN, Pa. — Barack Obama on Saturday accused rival Hillary Clinton of internalizing "a lot of the strategies and tactics that have made Washington such a miserable place," while Clinton implied that Obama's sensitivity in their last debate showed that he isn't ready for the "overwhelming" pressures of a general election.
By foot, bus and train, the two Democratic presidential rivals criss-crossed Pennsylvania making competing pitches for voters in Tuesday's crucial primary.
Obama, the underdog in this state, went on the attack, while Clinton's criticisms of her opponent were more subtle.
Obama accused Clinton of flip-flopping her positions on the Iraq war and trade policy to match popular opinion. He also organized a conference call in which Pennsylvania veterans who served in Bosnia slammed Clinton for her erroneous recollections of coming under sniper fire there while first lady in 1996.
For all of the campaign's recent controversies, from Clinton's Bosnia problem to Obama's recent gaffe about "bitter" voters, their closing arguments here boil down to what they've argued since the Iowa caucuses in January.
Clinton: That she's more tested and prepared, more substance over hype. Obama: That he represents a politics that is new and untainted while Clinton embraces a more cynical status quo.
"This is such an important election, I don't want to just show up and give one of those whoop-de-doo speeches and just kind of get everybody whipped up and make everyone feel great and try to convince some of you to be for me," Clinton told voters at a morning rally in West Chester, the first stop on a daylong bus tour.
"I've tried to be very specific in this campaign - I have offered solutions."
Obama, who faced a question in the Wednesday debate about whether his infrequent wearing of flag pins means he doesn't believe in the American flag, went out of his way to put his patriotism on display.
His campaign arranged a populist-style whistle-stop by train through towns west of Philadelphia. The train, draped in red, white and blue bunting, made a "slow roll" through some towns and stopped at others.
At an outdoor rally at the station in affluent Wynnewood, where Obama has many supporters, he told a crowd of 6,000 that he and Clinton would work together to defeat Republican John McCain in the fall no matter what, but that as long as there was a primary contest Democrats should know the difference between them.
"Her essential argument is you can't really change Washington," Obama said. "She says that 'lobbyists represent real Americans,' that's a quote. She's taken different positions at different times as fundamental as trade or even a war, to suit the politics of the moment. And when she gets caught at it, the notion is, well you know that's just politics, that's how it works in Washington."
"I am not interested in having debates about flag pins, I'm interested in having a debate about how I'm going to put people back to work . . . and how we're going to get our troops home from Iraq," Obama said.
Obama made the "miserable" remark at another train stop, in Paoli. He began the day knocking on doors in Philadelphia.
While other primaries remain after this state's on April 22, Pennsylvania is important because of its large number of convention delegates (188), its history as a swing state in general elections, and its white working-class population whose level of comfort with a biracial candidate could give a clue about Obama's potential viability against McCain in a general election.
A Clinton win could keep her campaign alive. But if Obama, who has closed Clinton's lead considerably in polls, comes close, he hopes it will convince superdelegates to close ranks around him.
Clinton aides argue, conversely, that if Obama can't beat Clinton in Pennsylvania after outspending her 3-to-1, his status as the national front-runner should be questioned.