One of the coolest things about Barack Obama appearances was when he'd finish and they would play "Signed, Sealed, Delivered" by Stevie Wonder. It was an electrifying scene but it was also just downright charming for a politician to finish speaking and have the next words be, "Like a fool I went and stayed too long."
Meanwhile McCain would try one song after another without permission and then the musicians would hold a press conference to denounce him for using their song.
Quite a contrast.

without permission

I'm hazy about this stuff. My understanding is as long as a venue is up to date on their ASCAP (or whatever the music entity is) fees, they can play whatever they want, with or without the artist's permission. Same goes for radio hosts. Chrissie Hynde must go insane every time she passes by the Rush Limbaugh show.

Watching Heart go after McCain during the campaign and ask him to quit playing Barracuda befuddled me. I don't think Heart had a leg to stand on, which is why they never sued. What say does an artist have if a song has been properly licensed and the appropriate fees have been paid?

Just asking...

The legalities are hazy to me, but it does seem that a song can be licensed to be used at an event without the artists' permission. More accurately, they've already agreed to that sort of thing in general terms although some artists have exceptions for political use written into their contractual arrangements. But here's one paragraph I found about the Palin campaign:

If the campaign chooses to continue playing "Barracuda," and so much so that it becomes associated with Palin, the Wilson sisters could have a legal claim. They might argue a violation of their "right to publicity," which protects a person from having her identity used for marketing purposes. Such protections vary by state and tend to apply to commercial products, not political messages.

Any lawsuits would be difficult. I'm sure all these campaigns are temporary entities unto themselves so suing them wouldn't be as easy as suing John McCain, the individual. But getting permission definitely would help from a PR standpoint. McCain had a seemingly endless list of musicians trooping up to a microphone to object including John Mellencamp, Van Halen, Heart, and Jackson Brown.
The classic was Ronald Reagan's use of Bruce Springsteen's "Born in the USA" that proved the Gipper didn't understand the lyrics.

GOD, I love Stevie Wonder. Nothing in the world is better to me than that man - and carrot cake. And bacon.