Donald Trump's had a rough couple of weeks since the GOP convention. A string of self-inflicted controversies and plummeting poll numbers have some observers speculating about the possibility of a Hillary Clinton blowout in November.

Trump is facing some polling difficulties not because Hillary Clinton is particularly popular but because he is proving to be surprisingly unpopular among Republicans. And a recent Reddit thread provides some fascinating first-person testimonials to back that up.

In the popular AskReddit section of the site, a user posted the following question: "Former Trump supporters of reddit, what was the final straw for you?"

Reddit users tend to be younger, more male, and more left-leaning and libertarian than the population at large, so this is by no means a scientific or representative sample. But the responses do highlight a couple of points of frustration with Trump among people who had once been inclined to support him. Some themes stand out.

His temperament is a big turnoff.

GhostalMedia said "I was on the maybe fence for a while. I liked the idea that he didn't give a f***, wasn't being pressured by lobbyists, and had some party agnostic ideas." Now, the user says, "I'm over it. He's a textbook demagogue. Blame the media if they point out lies, appeal to anger, blame the others, and dance confidently in front of the camera."

Hyon420 agreed. "I'm with you 100%. I really wanted the anti-politician, not the anti-human." Asked to elaborate by another user, Hyon420 elaborated: "The system is so corrupt that I crave an outsider. Hillary (and the Clinton Foundation) are openly corrupt and sinister, so my hope was that Trump could represent the people. I thought that since [he] had so much money, he'd be immune from corruption. It looks more and more like he had no intention of beating Hillary."

Mightnifty was on a similar page. "I was a huge fan of Trump as a kid. I would watch The Apprentice and wanted to be a successful businessman like him. To have money and power and knowledge of businesses, that was my dream. Then he decided to run for president and all this crazy sh** came out of his mouth and I noped the f*** out of there."

"Whenever he asked three times during a security meeting, 'If we have nukes, why don't we use them?'" thummel said. "He does not have the temperament and restraint to be a commander in chief and i'm equally terrified of him and hawkish killary becoming President."

Trump's climate skepticism also isn't winning him fans among young voters.

Reddit users tend to be skeptical of religion and big supporters of science — communities for atheism and science are among the site's largest, with over 2 million and 12 million members, respectively. That showed in many of the answers.

"I was on the fence until he said global warming was a hoax," WubbaLubbaDubStep said.

"When he and Clinton both got the nomination for their respective parties, I was actually leaning more toward Trump," Scratch_That_Itch said. "However, his denial of climate change completely changed my mind. I'm not one to get caught up in the doom and gloom of many articles about the climate changing, but there is absolutely ZERO reason not to invest time, money, and energy into renewable/cleaner power sources."

Two words: Mike Pence.

This was something of a surprise. Many Redditors pointed to the selection of Pence as Trump's running mate as the last straw.

"I was excited about having a republican candidate who wasn't a far right wing religious zealot," Ahoya21 said. "Then he picked Pence as a VP and I thought, well f*** I may actually have to vote for Clinton."

"I knew he was unfit to be POTUS," 2ndBestUsernameEver said. "but was still going to 'protest vote' for him because I'm in a safe blue state and don't like Clinton. Him picking Pence as VP was the last straw for me because I can't justify voting for a religious zealot to have the chance of becoming POTUS."

BassAddictJ had a one-word answer: "Pence."

Trump's treatment of veterans.

Many users also cited Trump's response to the Khan family as a decisive factor in their decision to vote for someone else.

"I'm from the New York City area. Trump is an absolute legend," Dooniel said. "So naturally, when he ran for president, it was great. He cut through the BS of every other Republican candidate; he was actually talking about genuine ideas, genuine solutions for America's problems instead of the usual Bush, Rubio crap ... Even his more radical (xenophobic) ideas — the Muslim ban, the wall — while not appealing to me, genuinely reflect how many American people feel."

But that changed with the attacks on the family of Humayun Khan, Dooniel said.

"But then he took a shot at Mrs. Khan. A Gold Star mother. I couldn't figure out what sort of calculation he made for that one — the entire right united against him on that, and my vision of genius PR master Trump just didn't fit. It reminded me of how he insulted John McCain for getting captured — while he himself is a draft-dodger."

Spmark333 echoed similar sentiments. "I only supported him for like 2 months (after the primary was over and there wasn't another choice), but once he went after the Veteran's family I had enough and jumped on the Johnson/Weld train. No matter what someone's parents believe there's no reason to attack a family who lost a son dying for our freedom."

"So, I'm a democrat who has become disillusioned with the current Democratic party and I've never been a big Republican fan," zerbey added. "It was funny at first, then I thought hey why not he's at least different. Then I thought, maybe it'll be good to have a different type of politician. It stopped being funny when he started making more and more ludicrous claims and getting into silly fights that he clearly cannot win ... The final straw was the whole fight over the soldier's family, that's not the type of President I want running my country."

That all being said, Reddit doesn't have much love for Hillary either.

Many users said they'd be casting their vote for Libertarian Gary Johnson. "Now I've no idea who I want to support in 2016, but I'm learning towards Johnson," zerbey said.

"Do your research on Gary Johnson and Jill Stein," masterofevolution224 pleaded. "I promise one of these candidates will resonate with you. Even if neither of them win, at least you can say you voted."

ShinySh4ky pointed to his discovery of the Johnson campaign as a turning point. "Finding out there was an alternative that wasn't hillary. #FEELTHEJOHNSON"