However, Larry Hatheway, chief economist at asset management firm GAM and a joint American-British citizen, told CNBC that this type of support reinforced Clinton's image as the "establishment" candidate.
"Hillary Clinton, the Democrats and Obama and so forth have been associated with what were called the cultural elite of the United States and therefore endorsements that come from that set, for them, probably actually reinforce perceptions among those that feel disenfranchised that it is a little bit of 'us versus them," Hatheway said.
Celebrities who have expressed support for Trump include American footballer Tom Brady, and Clint Eastwood.
"When someone from that milieu — Clint Eastwood, whoever it might be — supports Donald Trump, it probably carries a bit more weight because it is, in fact, running against perhaps that tendency (for celebrities to support Clinton)," Hatheway said.
Analysts said Clinton was viewed as the victor of Monday's debate by financial markets, with global stocks rallying overnight and on Tuesday. However, an online CNBC poll found 67 percent of 1.2 million voters saw Trump as the victor.
As of last week, NBC News put support for Clinton at 45 percent, versus 40 percent for Trump.
Hollywood star Goldie Hawn told CNBC on Wednesday that she thoughtClinton was best-equipped to be the next U.S. president.
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