U.S. Rep. Peter Roskam took the stage at a cavernous Marengo forklift factory to make his pitch. “The economy is a growing pie, and we want it to grow,” said the six-term Republican congressman from Wheaton who represents the 6th Congressional District – a political battleground he will defend in November. Standing in front of a roomful of UniCarriers employees Wednesday morning, Roskam elaborated on the vision propelling his campaign. “We want it to expand.