Conservative interest groups have dumped well over $20 million into congressional races so far this year, outspending their liberal opponents 4 to 1 and setting off a growing panic among Democrats struggling to regain the House and hold on to their slim majority in the Senate. The surge suggests that big-spending super PACs and nonprofit groups, which have become dominant players in the presidential race, will also play a pivotal role in House and Senate contests that will determine the balance of power in Washington in 2013. The money could be particularly crucial in races below the national radar that can be easily influenced by infusions of outside spending. One example came this week in Nebraska, where a dark-horse Republican Senate candidate upset two better-funded rivals in the GOP primary thanks in part to a last-minute, $250,000 ad buy by a billionaire-backed super PAC. And in Indiana this month, veteran Sen. Richard G. Lugar was ousted in the GOP primary by challenger Richard Mourdock with the help of millions of dollars in spending by conservative groups. The Club for Growth, which backed a losing candidate in Nebraska, spent more than $2 million to help Mourdock in Indiana.
“We’re just getting started,” said Club for Growth spokesman Barney Keller, who said the group will soon begin training its fire on Democrats. “Our group has already had an impact on what the composition of Congress is going to look like next year. That’s our whole goal is to have an impact, to improve the gene pool in Congress.” While Democrats welcomed the unexpected chance to compete for the Indiana seat, many are increasingly worried about the threat posed in the fall by well-funded conservative groups.