The news today that Americans for Prosperity (AFP) is launching $500,000 worth of new TV ads in Arizona targeting Democratic Reps. Ann Kilpatrick, Harry Mitchell and Gabrielle Giffords is the latest indication that conservative group will be a major player in the November midterm elections. The new AFP ads come a week after the group's sister organization, Americans for Prosperity Foundation, announced plans to launch a $4.1 million ad campaign targeting 24 competitive House seats in 11 states -- a buy that may well be the biggest of the summer. Americans for Prosperity's increasing involvement in races this cycle has caught the attention of the New Yorker, which earlier this week published a lengthy investigative piece on the organization's co-founder, billionaire David Koch, and his brother, Charles Koch. The group has also drawn the fire -- and ire -- of national Democrats, including President Obama, who mentioned it by name in a speech at an Austin fundraiser earlier this month. "Right now all around this country there are groups with harmless-sounding names like Americans for Prosperity, who are running millions of dollars of ads against Democratic candidates all across the country," Obama said. "And they don't have to say who exactly the Americans for Prosperity are. You don't know if it's a foreign-controlled corporation. You don't know if it's a big oil company, or a big bank." The Fix - Who is "Americans for Prosperity"?