Political profiteering by local television stations just goes on and on. Using publicly owned airwaves, stations last year raked in hundreds of millions of dollars in political advertising yet expended precious little of it back into political news coverage. And Congress, it appears, is going to let them multiply their earnings opportunities without exacting any assurance that they’ll change their ways.

Each election cycle, the Norman Lear Center at the Annenberg School for Communications of the University of Southern California analyzes the amount of time major TV stations around the country devote to political coverage and advertising. The bottom-line result for 2004 was that 64 percent of the 4,300 local news broadcasts in 11 major markets contained at least some political coverage. But presidential coverage accounted for 55 percent of all political stories. Lesser races accounted for only 8 percent.

“Eight times more coverage went to stories about accident injuries, and 12 times more to sports and weather, than to coverage of all local races combined,” the study found. Presidential election coverage roughly matched presidential election advertising, yet “by contrast, in races for the U.S. Senate, ads outnumbered news by as much as 17-to-one, and House races, by as much as seven-to-one.” The study didn’t calculate the financial implications of those numbers to the stations, but it’s clear that it represents a bonanza.

Local stations are on the verge of reaping an even larger bonanza as they move from analog to digital transmission. Each station will be able to split its signal into five or six broadcasts. As Roll Call reported Monday, a fight is on in Congress over whether to force television stations to meet a conversion deadline so that part of the spectrum can be transferred to homeland security communications uses. The National Association of Broadcasters, the lobby of the network TV affiliates, is fighting the deadline because most viewers don’t yet have digital TV conversion boxes.

That fight is not our concern. This is: Local TV stations ought to be required, as part of their conversion, to devote part of their broadcast time to local civic affairs and election coverage. This was a recommendation of a 1999 commission headed by then-Vice President Al Gore. It’s been ignored by the Federal Communications Commission but advanced by the nonprofit Alliance for Better Campaigns, which has now merged into the Campaign Legal Center. The idea has been part of legislation introduced in the past by Sens. John McCain (R-Ariz.) and Russ Feingold (D-Wis.).

Various proposals exist to auction the newly freed-up spectrum and use the proceeds to reduce the federal deficit. McCain and Feingold propose to charge stations a user fee and devote part of the proceeds toward helping candidates buy TV ads, thus, hopefully, reducing the need for fundraising. We urge Congress to remember: The public owns the airwaves, not local stations. They should be used to serve the public interest.