Democratic presidential candidates Hillary Rodham Clinton and Barack Obama and their allies are expected to flood the airwaves with political advertising in the weeks before the April 22 Pennsylvania primary.

Rob Owen of the Post-Gazette reports that the price of a single 30-second political ad during the 11 p.m. local news can approach $2,000.

The two candidates spent $12.5 million in Ohio and Texas alone during the two weeks before those states held primaries.

Radio will benefit as well as TV; according to Owen, “Obama for President” was the number one radio advertiser in the nation during the last week of February.