Washington (CNN) - Americans for Prosperity is once again putting its money where its mouth is.
The conservative non-profit political advocacy group backed by the deep pockets of billionaire industrialists David and Charles Koch announced Wednesday that it's going to run new television commercials in a key Senate race in Colorado and an important House battle in New Hampshire.
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The spending on the new ads brings to more than $35 million the amount the conservative group has shelled out to run TV spots in key Senate and House races around the country. The vast majority of the commercials highlight how the group says the Affordable Care Act, better known as Obamacare, has negatively impacted average Americans. The commercials criticize Democratic lawmakers and candidates for their support of the health care law and praise Republicans for their opposition to the measure.
The spot in Colorado touts Rep. Cory Gardner, the two-term GOP congressman who's challenging Democratic Sen. Mark Udall in November. Flipping Udall's seat and five others held by Democrats would give Republicans control of the Senate.
"Congressman Cory Gardner supports building the Keystone pipeline, to create new high paying energy jobs. He's focused on spending less and spending smarter and voted to balance the budget. And Cory stood against Obamacare and for real health care reform," says the narrator in the commercial.
AFP tells CNN that it's spending $150,000 to run the ad for about 10 days in Colorado.
Senate Majority PAC, the leading pro-Democratic outside group that's pushing back against AFP's efforts, says it has spent $11.1 million this cycle to run spots in support of Democrats and critical of Republicans in key Senate races. Senate Majority PAC says it will continue to fight AFP and other pro-GOP outside groups.
The group says starting Thursday it will spend $700,000 to run a new ad in Colorado for three weeks.
"Congressman Gardner has consistently advocated and advanced a reckless and irresponsible agenda, and we are going to make sure voters are keenly aware of the stark choice in this election," Senate Majority PAC campaigns director Ty Matsdorf told CNN.
House races also in spending spotlight
While the Senate races grab more attention, some House contests are also seeing a major infusion of spending by AFP. The group tells CNN that around 30% of its ad spending goes towards around a dozen House races. The latest spot is in New Hampshire's 2nd Congressional District, where first-term Democrat Ann McClane Kuster faces a tough re-election.
"Obamacare is hurting us, yet Congresswoman Ann McLane Kuster defends Obamacare," says the announcer in the commercial.
"AFP is committed to holding politicians accountable for their support of bad legislation like Obamacare, which is wreaking havoc on the lives of millions of Americans, and is particularly bad in New Hampshire," said AFP president Tim Phillips, in a statement.
The group tells CNN they'll spend $700,000 to run the ad for three weeks.
Since the 2010 Supreme Court "Citizens United" ruling opened the floodgates for spending by outside political groups, AFP's been a major player. In the 2012 election cycle, the group spent around $130 million, with a quarter of that cash going to run ads urging voters to say no to President Barack Obama.
So far this cycle, AFP's shelled out far more than any other outside group, and by November's election its spending may come close to its 2012 tally.
In the past couple of months, Senate Majority Leader Harry Reid has taken to the floor of the Senate to slam the Koch brothers.
The Nevada Democrat has described them as "un-American," having "no conscience" and has said that many of AFP's ads are untrue.