The National Republican Congressional Committee is launching attack ads in 27 House districts, blasting Democratic incumbents with a boatload of opposition research.

Most of the new ads focus on specific issues rather than on tying the candidates to President Obama and the House Democratic leadership, as many earlier ads have done. Though a few in more conservative districts still use that as the main line of attack.

The targets include 10 incumbents: Reps. John Barrow (Ga.), Lois Capps (Calif.), Ben Chandler (Ky.), Mark Critz (Pa.), Kathy Hochul (N.Y.), Larry Kissell (N.C.), David Loebsack (Iowa), Jim Matheson (Utah), Jerry McNerney (Calif.) and Nick Rahall (W.Va.), as well as former Reps. Ann Kirkpatrick (Ariz.), Carol Shea-Porter (N.H.) and Charlie Wilson (Ohio).

The other targeted Democrats: Ami Bera, Jose Hernandez and Scott Peters in California; Joe Miklosi in Colorado; Al Lawson in Florida; Tammy Duckworth, David Gill and Cheri Bustos in Illinois; John Oceguera in Nevada; Sean Patrick Maloney and Julian Schreibman in New York; Pete Gallego in Texas; and Pat Kreitlow and Jamie Wall in Wisconsin.

Five of the targeted districts are in California, four are in Illinois and three are in New York. All three are blue states that have a high number of competitive seats this election because of redistricting. For a full breakdown of how each seat leans, check out The Hill's House Race Ratings.

The ad against Bustos, who is challenging Rep. Bobby Schilling (R-Ill.), is typical to this buy: It hits Bustos for voting to spend money locally and questions her ethics. Watch it here.