The National Republican Congressional Committee launched its air assault against Rep. Jim Matheson, D-Utah, on Friday using two-year-old footage from a state Democratic Convention where the congressman noted his support for the economic stimulus bill.The 30-second spot hits Utah stations today and runs through the week, costing $250,000. It is part of an early wave of ads that will only increase in intensity as Election Day approaches. So far, the American Chemistry Council has ran an ad touting Matheson as a politician serious about job growth and his Republican challenger Mia Love has produced a spot highlighting her experience as mayor of Saratoga Springs.Get ready, more are coming and more, like this NRCC ad, are likely to be negative in tone. Matt CanhamTwitter: @mattcanham