Mar 17, 2014 1:27 PM by David Randall
DENVER (AP) - Billionaire brothers behind nationwide attacks on Democrats are turning their attention to Colorado, where incumbent Sen. Mark Udall is seen as vulnerable.
In a statement Monday, a group known as Americans for Prosperity announced a new TV ad campaign linking Udall to health insurance reform. The group called it part of a nationwide effort against Obamacare.
Udall's office responded with a statement accusing Kansas-based Charles and David Koch, who have a chemical and textile empire and helped found Americans for Prosperity, of pouring "tainted money" into the Colorado race.
If they can gain six seats in the November midterm elections, Republicans will control the Senate. In Colorado, Rep. Cory Gardner is seen as the chief challenger to Udall among several politicians vying for the Republican nomination.