The race to become the DFL challenger who will try to unseat Republican U.S. Rep. Chip Cravaack this fall is proving to be costly for the parties involved. Campaign finance reports show Sen. Tarryl Clark has already spent more than three times the total she raised in the first 25 days in July, and Congressman Rick Nolan and former Duluth City Council Member Jeff Anderson have also spent more cash than they've taken in.