''What we need now is not just a regime change in Saddam Hussein and Iraq, but we need a regime change in the United States,'' Kerry said in a speech at the Peterborough Town Library. By echoing the ''regime change'' line popular with hundreds of thousands of antiwar protesters who have demonstrated across the nation in recent weeks, the Massachusetts senator and Democratic presidential contender seemed to be reaching out to a newly invigorated constituency as rival Howard Dean, the former governor of Vermont and a vocal opponent of the war in Iraq, closes in on Kerry in opinion polls....''I don't think they're going to trust this president, no matter what,'' Kerry said. ''I believe it deeply, that it will take a new president of the United States, declaring a new day for our relationship with the world, to clear the air and turn a new page on American history.''