Michele Bachmann is defying a cease and desist letter and is continuing to use Tom Petty's music without his permission. Here's why. 

Congresswoman Michele Bachmann officially threw her hat into the ring for the White House in 2012 and kicked off her campaign with a big rally Monday in her hometown of Waterloo, Iowa.

As she stepped off stage, Tom Petty's "American Girl" was blaring through the speakers. Petty caught wind of it and fired off a cease and desist letter demanding that Bachmann immediately stop using the song as part of her campaign. His publisher, Wixen Music Publishing Inc. said that when candidates use music, that sends a message that their campaign is endorsed by the artist, which isn't true.

Well, Bachmann was back at it Wednesday in South Carolina. She was rallying her constituents and supporters and as she stepped off stage, 29 seconds of "American Girl" played, right up until "raised on promises" was sung. It was abruptly cut off by Katrina and the Waves' "Walkin' on Sunshine". No word as to why the choice to use that particular song, and the folks associated with the group have said nothing about it - so far.

Tom Petty's camp is refusing to comment on the matter and the Bachmann people have also been tight lipped. Could this mean that there is impending litigation?

Perhaps, however, the rules surrounding candidates for public office using music without the artist's permission are a bit murky. I am not a lawyer, but legal eagles say that if a candidate purchases a license from ASCAP to use a particular song, they can use it all they want whenever they want. Others agree with Wixen, saying that usage of a song means that the artist endorses the candidate which is not always the case. (Remember John Mellencamp shutting down John McCain in 2008?)

The issue has yet to be tried in a court of law or even heard by a judge, but most candidates stop using the song when an artist says something.

Stay tuned.