If you ask Donald Trump, his endorsement is the most coveted in the race for the GOP presidential nomination. But he may be the only one who thinks so.

Despite Trump's claim that "millions of people are waiting" for his endorsement and that "everybody wants it," polling shows that few voters will be swayed by the real estate mogul's pledge of support, which he gave to Mitt Romney on Thursday.

Nearly two-thirds - 64 percent - of likely Republican voters say Trump's support has no impact on their vote, according to a Pew Research poll released last month.

But that voter indifference is not unique to Trump. The same poll found likely GOP voters would be equally unswayed by endorsements from political big-hitters John McCain, Sarah Palin or Herman Cain.

"There are not very many people in very many places who  can actually deliver votes on Election Day," said Phil Noble, a longtime political consultant and founder of Politics Online. "People pretty much make up their own mind, and they're pretty independent."

Ron Paul, for example, is polling in last place among the GOP candidates despite the backing of big name celebrities such as Vince Vaughn, Kelly Clarkson, Barry Manilow and Snoop Dogg, none of which have given Paul a perceptible boost in the race.

The most influential endorsement in the GOP primary may actually be Paul himself, said Larry Sabato, director of the University of Virginia's Center for Politics.

"Ron Paul's endorsement will actually matter more than that of the other [former GOP] candidates, because he has such intense support," Sabato said. "There is no doubt many of the Paulites would respond if given the call."

Generally speaking, Sabato said endorsements matter far more in the money race than the vote tally.

"There is not a direct vote transfer. It's all indirect," Sabato said. "Endorsements can transfer money and media attention. They attract the cameras."

In Trump's case, while his announcement of support Thursday spawned a media frenzy, his endorsement could actually do more harm than good.

About 20 percent of respondents in the Pew poll said they would actually be less likely to support a Trump-backed candidate.  And a full one-third of respondents in a September Fox poll said they would be less likely to vote for the candidate Trump endorses.

Nevertheless, GOP candidates lined up to meet with the Donald. Of the four remaining contenders, only Ron Paul has not paid homage to Trump, refusing to participate in a Trump-moderated debate and not seeking a Trump Tower meeting with the billionaire.

Newt Gingrich, on the other hand, has actively courted Trump's endorsement, which original reports said would go to the former House speaker.

"Of course I want his endorsement," Gingrich told reporters after his December meeting with Trump at Trump Tower in New York City.

In an interview on "Good Morning America" earlier this week, Trump made his support out to be a hot commodity, telling ABC's George Stephanopoulos that Romney and Gingrich "both want my endorsement."

In his book, Trump was less humble about his prospective endorsement.

"Some magazines have said I am the single most important endorsement a presidential candidate can have," Trump wrote in ""Time to Get Tough: Making America #1 Again." "I don't know if that's true, but it wouldn't surprise me."

Realistically speaking, though, Trump's decision to endorse Romney may translate to a few high-dollar fundraisers, but will make virtually no impact on Election Day, Noble said.

"It'll be in the media, all the talking heads will talk about it, and everybody will try to make a big deal out of it in some way, but I think its impact is not worth the effort," Noble said. "It will be great sound and fury all to no effect."