Concord, N.H. ? Democrat John Kerry accused presidential rival Howard Dean of lacking principles and flip-flopping on key issues Thursday, hoping to convert the front-runner’s fumble over the Confederate flag into a sweeping indictment of Dean’s policies and personality.

“I think Americans deserve straight talk. I think they ought to know who Howard Dean is,” the Massachusetts senator said.

The Dean campaign immediately shot back.

Dean’s spokeswoman said Americans deserved to know why Kerry had struggled to explain his support for President Bush’s Iraq war resolution. “It’s become increasingly clear that John Kerry is a heck of a lot better at formulating negative attacks than formulating a straightforward position on Iraq,” said Tricia Enright.

A new American Research Group poll showed Dean with a 14-point lead over Kerry in New Hampshire, a state each must win.