Costas Panagopoulos, an assistant professor of political science at New York’s Fordham University, has pointed out that Oprah Winfrey’s support of Obama may have done little for the Obama campaign, and may have actually hurt Oprah’s personal popularity.

To be sure, Oprah remains one of the most popular figures in America, but recent data suggest her popularity has eroded. One possible explanation for this decline is that her endorsement of Obama and her support for him may have done more to damage impressions of her than to strengthen support for Obama. Then again, Obama may become the next president of the United States, and he may feel he has Oprah partly to thank for going out on a limb for him — not a bad situation for the talk show queen.

Still, a lesson celebrities may extract is that political endorsements carry the risk of alienating fans, often without the reward of considerably boosting support for the candidate. While celebrities are certainly entitled to express their political beliefs — just like every other American — it is possible that the public prefers high-profile entertainment personalities to stay on the tube and off the stump.