-------------------------------------------------------------------------------- Posted on Fri, Aug. 27, 2004 Polls show Swift boat dustup is hurting Kerry WASHINGTON — The presidential race remains a toss-up amid signs that a controversy over Sen. John Kerry's Vietnam service has hurt the Democrat, but not necessarily with lasting consequences. Three polls released Thursday show that ads questioning Kerry's service as a Navy Swift boat officer in Vietnam have eroded some of the benefits gained from Vietnam imagery employed at the Democratic National Convention last month. One poll, by the Los Angeles Times, showed President Bush gaining the lead for the first time. Another survey— the...