Independent groups may be outspending Minnesota’s candidates for governor over the airwaves, but they aren’t alone.

Congressional candidates have already spent $1.6 million on Twin Cities television ads since the primary – almost four times their gubernatorial counterparts.

The majority of that money has been shelled out by Republican Rep. Michele Bachmann and her DFL challenger, state Sen. Tarryl Clark, who have just begun to unleash their massive war chests on TV.

The two have invested a million dollars on ad buys since the primary, about $650,000 of which came from Bachmann and $380,000 came from Clark. Those totals account for ads on KARE, KMSP, WFTC, KSTP, WCCO and Comcast.

Compare that with Emmer, the top gubernatorial spender, who has only invested about $250,000 in television time.

Bachmann’s ads have targeted Clark’s tax record in the Legislature. Clark has run one bio ad and another highlighting Bachmann’s criticism of a White House plan for BP to create an independent fund to pay victims of the oil spill. She also invested in an ad before the primary.

The pair has only purchased time through Sept. 19, so more money is likely on the way.

Bachmann isn’t the only incumbent lawmaker pushing her message through area TV sets, however.

Republican Rep. Erik Paulsen, a freshman whose district covers western suburbs, has spent just over $500,000 to run ads on local stations through Nov. 2. Though his district voted for Obama in 2008, Paulsen’s significant television presence over the next several weeks will likely prove a major hurdle for DFLer Jim Meffert, who has struggled to raise money.

Democratic Rep. Tim Walz has also sent about $120,000 to area stations, so far to run one ad that touts his work with veterans while in Congress. Walz represents southern Minnesota, so he has also likely bought time in the Mankato and Rochester markets as well.

His opponent, Republican Randy Demmer, has yet to release any television ads.