Yes, political ads are supposed to be at the lowest ad rate, but consider the number of times these ads run in the last month of the campaign. They push out ads from steady customers of radio/TV outlets...
Well that is a point I had made earlier, yes, they push out ads from regular advertisers for sure - which is why it is not a dollar for dollar situation.
If those two stations lost 10 million in ad revenue from the campaigns and PACS, they probably recouped several millions from regular ad buyers who did not get pushed out. I never said it wasn't a money maker, just not the obscene cash cow it may seem from the outside.