Media playback is unsupported on your device Media caption Celebrities' plea to Republican Electoral College voters

It is meant to be a heartfelt appeal from some of the US's most recognisable faces.

Actors Martin Sheen and Debra Messing are joined by a host of other celebrities - including musician Moby - to ask Republican electors to not cast their vote for President-elect Donald Trump on 19 December.

The argument put forward in the Unite for America clip is simple - Mr Trump is not fit to be president of the United States, and therefore members of the Electoral College should block his entry to the White House.

"Our founding fathers built the Electoral College to safeguard the American people from the dangers of a demagogue and to ensure that the presidency only goes to someone who is, to an eminent degree, endowed with the requisite qualifications," Sheen explains in the video.

Celebrity power

Mr Trump, the celebrities continue, is not "highly qualified for the job" - and therefore the electors could, and should, prevent him from taking office.

In theory, the Electoral College could do this: It would take 37 Republican electors to vote for someone other than Mr Trump - thereby taking the party under the 270-vote threshold necessary for victory - to technically block his path to the White House.

Image copyright AP Image caption Hillary Clinton was supported by a host of celebrities - but failed to win the presidency

It is the latest stance taken by celebrities against Mr Trump's impending leadership. Others have been less direct - designers refusing to dress future First Lady Melania Trump, or rejecting offers to sing at the inauguration.

In stark contrast to his predecessor Barack Obama, only one A-list celebrity - Kanye West - has publicly endorsed Mr Trump since his election.

But in reality, how much does any of this matter - and how effective is such a direct plea to a group of Republicans?

If you believe the New York Daily News, not very.

"This video of celebs pleading with the Electoral College is why Hillary Clinton lost," the newspaper's website proclaimed in a headline.

Mrs Clinton did have a lot of celebrity supporters - on election night, actress Lena Dunham, singer Lady Gaga and comedian Amy Schumer were all in New York to support the Democrat they hoped would become the first female US leader.

Image copyright Instagram/LenaDunham Image caption It was thought millennial favourites like Lena Dunham (pictured), who have large social media followings, would bring out the young vote

They had all been vociferous campaigners for Mrs Clinton, as had Beyonce, whose plea to fans to vote for Mrs Clinton has had 2.4 million views to date.

In comparison, Mr Trump failed to attract any huge stars to support his campaign.

Yet Mr Trump won - suggesting celebrity endorsements do not have huge sway over voters.

Indeed, a study of possible voters in Ohio by professors Melissa Miller and David Jackson, both of Bowling Green State University, found that celebrity endorsements are potentially the opposite of helpful.

Writing in The Daily Beast, Mr Jackson revealed: "None of the celebrities [given as possible endorsers in the study] showed a net positive effect, and four of them showed double-digit net negative effects."

What's more, this election has taken a swipe at the so-called liberal elite - and nowhere is the elite more liberal than in Hollywood.

Image copyright EPA Image caption A-list celebrities have largely stayed away from Donald Trump, until Kanye West turned up for a meeting

Oprah Winfrey may be credited with playing a major role in Barack Obama's 2008 election, but a quick glance at the response on Twitter to the Unite for America video shows there is no appetite for the 1% to lecture the majority on how they should vote.

"You stick to pretending to be somebody else," wrote one. "Nobody gives the rear end of a rodent what you and your pampered friends think."

Another tweeted: "Y'all prove one thing. being a so-called educated intellectual doesn't mean you have common sense."

Meanwhile, a meme mused whether celebrities were more upset about the election result, of "finding out people don't give a **** about their opinions".

And despite the odd tweet praising them for being a "glimmer of hope in an era of hopelessness", even fellow liberals have questioned the point of such a video.

So with a backlash against celebrities, it seems highly unlikely their doom-laden words will sway Republican electors on Sunday.

There is, of course, one huge irony in all of this: Mr Trump has, arguably, only been elected to the highest office in the land because he is a celebrity.