Responding to concerns in his own party that he may have taken too long off the campaign trail, Senator John Kerry said Monday that he had plenty of time to define himself for voters despite millions of dollars worth of what he termed "the equivalent of nuclear attacks" on television by the Bush campaign that have cast him as a tax-and-spend liberal. "I'll put out a positive message, define myself to people — there's plenty of time here," Mr. Kerry, the presumptive Democratic nominee for president, told reporters for regional newspapers in wide-ranging discussions here on Monday, his first day...