President Bush today makes his seventh trip to Iowa since taking office. Bush will deliver a speech this afternoon at the State Fair. Senator Charles Grassley, who like Bush is a Republican, says Bush has a little explaining to do. Grassley says Bush should be prepared to answer questions from farmers who wonder why Bush’s U-S Ag Secretary hasn’t clarified the rules for just how much and when new federal farm payments will be coming. Bush held an economic summit in Texas yesterday to shore up public confidence in his ability to deal with the nation’s economic downturn. While in Iowa, Bush will stress the new “trade promotion authority” he was granted, albeit narrowly, by Congress. Grassley says Bush’s State Fair speech should deliver a “sharp” message about the evils of corporate greed. Bush’s economic theme echoes action in the corporate world, as executives from about 750 of the nation’s largest companies are required today to swear under oath that their companies’ financial records are accurate. Bush will speak tonight at a Des Moines fundraiser for Republican gubernatorial candidate Doug Gross.