I could be wrong, but I believe you can use up to 30 seconds of any song without requiring permission or payment of royalties.
EXCERPT:
WHEN CAN CAMPAIGNS USE MUSIC?
To use music in advertisements (television and internet), a campaign needs to receive legal permission from both the song’s publisher and the artist’s record label. The use of music at a live campaign event requires a “public performance” license, generally attained from one of the United States’ performing rights organizations. These organizations track the use of music and help distribute royalties from such events.
Technically, campaigns do not need to receive explicit permission from the artist to use their work, but it should be noted that even if a politician has all the requisite legal permissions the artist can still sue the campaign. The author(s) could make a claim to their “Right of Publicity,” which is a legal protection many states give celebrities and artists. The right of publicity generally protects the use of someone’s name and likeness for commercial reasons. However, this right is not yet nationally recognized. On the federal level, the Lanham Act protects an artist’s trademark or brand by offering protection against false endorsement in which the use of an artist’s work can imply the artist’s support. Politicians and their campaigns also need to acquire proper licensing from the publisher, record label, and venue.
What About Fair Use?
One of the most crucial pieces of U.S. copyright law, created to ensure the protection of free speech, is the doctrine of fair use. Fair use is defined as the copying of copyrighted material done for a “limited and ‘transformative’ purpose,” which may legally be done without the artist’s or license holder’s. However, fair use is loosely defined and limited by various court decisions.
There are two general categories of fair use. The first is commentary, in which a copyrighted work can be used in limited instances to provide examples and clarity–this is most commonly seen in scholarly works. The second category of fair use is parody, in which large sections of an original work may be copied and used in a satirical manner. When fair use claims make it to court, judges employ a four-point test to evaluate how the material was used and what the consequences were. Fair use claims are particularly strong when the use was for educational or informative purposes, or when the original work has been significantly modified to create something new.
When used to set a mood or accompany a politician’s platform, the use of music on a political campaign is generally not protected under fair use. The parody of a popular song for a campaign may constitute fair use, but otherwise artists would still be entitled to the protections established above. Although campaigns are not often afforded fair use protections, these claims are looked at on a case-by-case basis. While there may be some cases in which fair use protects campaigns, generally speaking, that is not the case.
More at link:
http://lawstreetmedia.com/issues/politics/campaign-music-fair-use/