Supporters of real estate mogul Donald Trump argue that he's the one candidate that can win in November. Problem is, the numbers do not support their assertion.

Here is political scientist's Larry Sabato's map of a general election matchup of Trump vs. former Secretary of State Hillary Clinton:

While political circumstances can change in a heartbeat, Sabato's record of predictions tends to be impeccably accurate, and all of the polling data released so far substantiates Sabato's prediction.

The polling data consistently reveals Trump's unfavorability numbers at record highs, even higher than Clinton's, who would have the highest unfavorability numbers for a presidential candidate if Trump wasn't running. Additionally, Trump is the only remaining Republican candidate that is consistently clobbered by Clinton in general election polling, and Trump's trend lines in those polls are sinking downward.

In fact, polling data from The Washington Post/ABC News suggests he's the most unpopular major party nominee in recent American history: (emphasis bolded)

Three-quarters of women view him unfavorably. So do nearly two-thirds of independents, 80 percent of young adults, 85 percent of Hispanics and nearly half of Republicans and Republican-leaning independents.

Those findings, tallied from Washington Post-ABC News polling, fuel Trump’s overall 67 percent unfavorable rating — making Trump more disliked than any major-party nominee in the 32 years the survey has been tracking candidates.

Trump's numbers among key-voting blocs are horrendous across the board, with the gray reflecting unfavorables and light-green reflecting favorables:

If Trump is the nominee, he has to climb out of a gigantic hole among the independents and more moderate Democrat swing voters he'll need to win in November, as well as shore up holes of support in the Republican base. It's not difficult to deduce that low turnout + inability to attract swing voters = landslide for Clinton in November.

The reason for Trump's massive unpopularity is that he has single-handedly transformed the Republican presidential primary from a substantive, serious race discussing issues of great importance while the country is on the brink into a personal mudslinging contest where Trump goes into the sewer to insult, disparage and berate anyone who dares to question his views, which clearly aren't particularly detailed or well thought-out.

"I fear we’re going to get blown out, and part of it is tactics, and part of it — quite frankly — is Donald Trump’s tweeting problems," radio host and constitutional scholar Mark Levin warned on Friday's radio show. "He tweets like he has Tourette’s, like he’s obsessed. Nothing personal, but it gets crazier and crazier, and it’s turning off more and more people."

Indeed, Trump's tweets resemble that of a Latin American dictator, and he's becoming increasingly unhinged with each day.

All signs point to impending doom in November for Republicans.