A super PAC designed to help House Democrats retake the majority in November is spending nearly $2.5 million on fall television air time reservations in six media markets in California, New York and Texas.

House Minority Leader Nancy Pelosi, a Democrat from California, speaks during a television interview on Capitol Hill in Washington, D.C., U.S., on Friday, July 27, 2012. Photographer: Andrew Harrer/Bloomberg

The group’s most expensive investment is in California, where it is reserving $1.2 million in the San Diego media market. Republican Rep. Brian Bilbray is facing a challenge from San Diego Port Commissioner Scott Peters there. An internal Peters poll conducted last month showed the race to be pure toss-up. Also in California, House Majority PAC is spending $285,000 in Palm Springs, where Republican Rep. Mary Bono Mack faces a challenge from Democratic physician Raul Ruiz.

In Texas, the group is reserving $415,000 worth of air time in San Antonio, where freshman Republican Rep. Quico Canseco is facing a challenge from Democratic state lawmaker Pete Gallego, who won the Democratic runoff in the 23rd District over former representative Ciro Rodriguez on Tuesday.

U.S. Rep. Louise Slaughter (D-N.Y.) (Mark Wilson/Getty Images)

In tandem with the Service Employees International Union, House Majority PAC had previously reserved $20 million worth of fall ad time, including in the Buffalo market, which reaches voters in Hochul’s Erie County-based race. The group is adding $120,000 to its previous $205,000 reservation there.

Outside groups have been lining up to lock in lower rates for the fall as the post-Labor Day stretch run approaches. The Democratic Congressional Campaign Committee has reserved more than $46 million for the fall, while the National Republican Congressional Committee has reserved more than $23 million.

The powerful GOP-aligned American Crossroads and Crossroads GPS have not reserved ad time for the fall in House races. The group’s main focus has been on the presidential contest and the Senate landscape. But the groups do intend to spend $300 million on congressional races and the presidential match.