The American Action Network and Congressional Leadership Fund, two Republican outside groups, are adding $4.5 million in advertising to help the GOP retain the House.

The groups have now combined to spend more than $21 million on House races.

Most of the buys are expansions of previous reservations rather than new targets. They added time to defend GOP Reps. Robert Dold (Ill.), Chip Cravaack (Minn.), Jim Renacci (R-Ohio), Frank Guinta (N.H.), Francisco "Quico" Canseco (Texas) and Sean Duffy (Wis.) and made buys to defend Republican Reps. Dan Benishek (Mich.) and Daniel Webster (Fla.). They're also targeting Democratic Reps. Lois Capps (Calif.) and John Barrow (Ga.) and open seats in Arizona, California and Illinois.

Most of these races are toss-up contests, though Capps and Webster had until recently been considered favorites in their race and Barrow had been viewed as an underdog. The buy for Webster was only $40,000, much lower than the other reservations.