The two men who are leading the races to win the Republican and Democratpresidential nominations were in Iowa on Sunday, trading jabs. Republican candidate George W. Bush said democrat Vice President Al Gore”trusted government” — and relies on polls rather than a politicalphilosophy to make decisions. Later in the day, Gore shot back, sayingRepublicans like Bush would squander the federal budget surplus on a riskytax scheme, and are refusing to grant Americans protections from H-M-Oabuses. Bush picked up the endorsement of former Governor Terry Branstad onSunday morning before heading to the Clay County fair. Gore grilled steaksat Senator Tom Harkin’s annual fall fundraiser, then met with a large groupof campaign workers who will help turn-out voters for Gore on Caucus night.On Saturday, Gore’s challenger, Bill Bradley, campaigned in Iowa — sayinghe doesn’t have to win Iowa’s Caucuses — just do better than expectationsand he’ll be poised to knock Gore out in the big day when states likeCalifornia, New York and Ohio hold their primaries.Gore has been getting the endorsements of labor groups, but Bradley says heplans to go after working families’ votes — particularly through a proposalto provide universal health care coverage to Americans.Bradley made his comments on Iowa Public Television.