Why exactly is payola illegal again?
Good question. How is it different than an infomercial?
They could say: these are the new hits Sony has paid us to play. People listen or they don't.
You would think most New York Times articles should be payola by the DNC.
I had this same question a while back. The best answer that I got (and that I agreed with) was that payola is illegal because it breaks the terms of the FCC license.
In other words, it would be fine for Serius or XM to take payola. In the case of "terrestrial" radio stations however, there is a legal agreement between the broadcaster and the U.S. Government (the valid representative of the owners of the RF spectrum) that the RF resource wouldn't be used for covert advertising.
They are not allowed to pay radio stations for particular artists to be pushed
It's something like this: since the RF spectrum (radio waves) are limited, the goverment (FCC) gives license to private broadcast stations to setup and transmit their content on those frequencies. In return, the broadcast station is supposed to operate "in the public's interest", e.g. no profanity (called "wardrobe malfunctions" these days), have a certain amount of socialist content (Sunday morning do-gooder infomercials), etc.
With that in mind, selling the airwaves the government licensed to you to the highest bidder (payola) is not considered fair play. IOW, you can't sub-lease the frequency that the FCC leased to you.