Actor George Clooney is planning a fundraising dinner to raise $10 million for President Barack Obama. Comedian Chelsea Handler and actor Tom Hanks are also Obama supporters.
Comedian Jeff Foxworthy, rocker Ted Nugent and country singer Trace Adkins have said they back the likely Republican nominee, Mitt Romney.
Star-studded endorsements may be attention grabbing, but does it influence voters?
Yes, it does, according to research recently published by a political scientist at the University of Tennessee, Knoxville.
Professor Anthony Nownes has found that celebrities who contribute to political campaigns can make a party more or less likable, depending on what voters think of the celebrities in the first place. His study is published in the current issue of "American Politics Research."
"Celebrities are always getting involved in politics and no one ever studies them," Nownes said. Although some academics may scoff at the importance of celebrity endorsements, Nownes argues that stars' political activity often makes news and that means it has the opportunity to influence public opinion."
Nownes quizzed more than 500 UT students about their reaction to the information that actress Jennifer Aniston has donated heavily to Democrats and quarterback Peyton Manning has donated to Republicans.
As for choosing students as his subjects, Nownes said research shows that "students are not much different than anybody else probably the only difference is they might be slightly more open to new information."
He said he chose Manning because, as a former UT gridiron star, he tends to be very popular among Tennessee students. He chose Aniston because most students would know her, but their opinion of her wasn't so clear cut.
"My results support the general notion that celebrity giving to political parties and their candidates affects people's views of the parties," Nownes wrote.
In his test cases, Aniston's support hurt the Democrats, while Manning's support helped the Republicans.
"If we think of the political parties as 'brands,' these results suggest that information about which celebrities 'use' each brand can affect people's attitudes about the brands," he wrote.
Further, he found, people sometimes change their opinions about celebrities after learning about their political leanings.
"Throwing their support behind a presidential candidate doesn't help the celebrities much," he said. "They don't get much positive from it, and they might get negative."
In this case, the data showed that people who are not particularly fond of Republicans were turned off by Manning's support for the Republicans and adjusted their opinions of him accordingly. Similarly, people who disliked the Democratic Party viewed Jennifer Aniston more negatively after learning about her support for Democrats.
"If this study has a practical meaning," Nownes said. "Its advice for celebrities: keep a low profile."
Explore further: Some characteristics increase the likelihood of getting married and living together