Seemingly immune to controversies and gaffes that would have ruined less ridiculous men, Donald Trump has topped every single poll taken on the Republican Primary race since late July.

But while his controversial views on everything from immigration to trade with China have appealed to a wide swathe of Americans, it has earned him few friends within the party.

Statistics site FiveThirtyEight has analysed the endorsements given to each candidate by their fellow party members, weighting the approval of governors, senators and representatives in descending order.

Endorsements, the site says, have proven a reliable indicator in past primaries, with 'party elites' gathering around the candidate they deem most acceptable, and rank-and-file voters usually following.

Looking at this year's primary races offers some surprising insights. Despite a rather drab campaign thus far, Jeb Bush leads the Republican pack with three senators and 20 representatives endorsing him.

Far more shocking is that Trump does not rank at all. To date, he has not recieved a single endorsement for an incumbent Republican, placing him behind stragglers Ted Cruz and Rick Santorum, who have one each.

Rather more predictably, Hillary Clinton has almost total Democratic backing, with 341 (weighted) endorsements to Joe Biden's 16.

FiveThirtyEight freely admits there have been exceptions to their findings - Hillary Clinton received more endorsements in 2008 than Barack Obama - but it's concerning news for Trump nonetheless.

Of course, like Obama, he could continue to ride a wave of popular support from outside the party, but it is unlikely even a dis-united Republican Party would allow Trump to take the nod.

The 'party elites' may also feel more at ease since Trump's pledge two weeks ago not to run as an independent candidate - a move that would likely split the Republican vote and guarantee a second successive Democrat in the White House.

Will Trump trump the odds and claim the Republican nomination, endorsements be damned?

It wouldn't be the most ridiculous thing he's ever done.