LOS ANGELES - The Democratic Congressional Campaign Committee (DCCC) will spend millions of dollars on television advertisements aimed at winning Republican-held seats in historically red Orange County this November, signaling a major play for seats the party must recapture in order to reclaim the House.

The DCCC will announce Tuesday it will spend $3.1 million on television spots in the Los Angeles media market, the most significant part of the committee's third wave of advertising buys this year.

The $5.1 million spent on California districts makes up about two-thirds of the $7.5 million in reservations the DCCC will begin making Tuesday.

Mike Bost Michael (Mike) J. BostMORE Democrats will buy $500,000 for five weeks of television time in Paducah, Ky., a media market that covers a Southern Illinois district held by Rep.(R). Democrats had previously reserved airtime in the St. Louis market, which also covers Bost's district.

The latest round of advertising buys brings the DCCC's total investment in television to about $20 million. The party laid out an initial round of $12.6 million in ad buys in May, in high-priority markets like New Hampshire, eastern Iowa, Minneapolis, Philadelphia and Miami. They quietly bought another $9.2 million in airtime earlier this summer.

Candidates, parties and outside groups have invested more than $280 million in television airtime in the battle for control of Congress this year.

Super PACs like the House Majority PAC, which supports Democrats, and the Congressional Leadership Fund, which backs Republicans, have reserved more time than the party committees, hastening a trend toward outside groups' spending domination that began after the Supreme Court's Citizens United decision.