WATCH: The video that suggests Trump is suffering from Alzheimer's

The most egregious parts of Donald Trump’s personality—his racism, his misogyny and his lack of scruples or ethics—have been on display for more than four decades. All of those traits have long been part of Trump’s unapologetic public persona. But in recent years, Trump has become an even more extreme version of himself. The behaviors that accompany that shift could be closely correlated with dementia and a general cognitive decline.

The blogger behind the Neurocritic laid out what he sees as proof of Trump’s mental deterioration. He notes that President Ronald Reagan was diagnosed with Alzheimer’s at age 83, though he began to manifest symptoms far earlier. Researchers have combed through records of off-the-cuff speeches Reagan delivered and found significant declines in his mastery of language. By his second term, Reagan’s speech showed a deep drop-off in the use of unique words; a marked increase in the use of non-specific nouns (thing, something, anything); an uptick in filler words (well, so, basically, actually, literally, um, ah); and a greater use of low-imageability, high frequency verbs (get, give, go, have, do).

Trump seems to have parallels in all these areas. He has become notorious for his word salads, incomprehensible soliloquies delivered at the speaking level of a fourth-grader. He frequently falls back on words like “tremendous” and often drags on without using specifics. Trump often speaks at length while saying nothing.

Alex Leo of the Daily Beast transcribed one sentence Trump delivered at a campaign stop in South Carolina, a series of dead ends, unfinished thoughts and ramblings:

Look, having nuclear—my uncle was a great professor and scientist and engineer, Dr. John Trump at MIT; good genes, very good genes, OK, very smart, the Wharton School of Finance, very good, very smart—you know, if you're a conservative Republican, if I were a liberal, if, like, OK, if I ran as a liberal Democrat, they would say I'm one of the smartest people anywhere in the world—it's true!—but when you're a conservative Republican they try—oh, do they do a number—that's why I always start off: Went to Wharton, was a good student, went there, went there, did this, built a fortune—you know I have to give my, like, credentials all the time, because we're a little disadvantaged—but you look at the nuclear deal, the thing that really bothers me—it would have been so easy, and it's not as important as these lives are (nuclear is powerful; my uncle explained that to me many, many years ago, the power and that was 35 years ago; he would explain the power of what's going to happen and he was right—who would have thought?), but when you look at what's going on with the four prisoners—now it used to be three, now it's four—but when it was three and even now, I would have said it's all in the messenger, fellas, and it is fellas because, you know, they don't, they haven't figured that the women are smarter right now than the men, so you know, it's gonna take them about another 150 years—but the Persians are great negotiators, the Iranians are great negotiators, so, and they, they just killed, they just killed us.

In the clip below, David Pakman shows how typical Trump bluster could actually be indicative of something more problematic. He compares old footage of Trump to the Trump of today, and looks at how Trump's physical problems may also be linked to Alzheimer's:

At 70 years old, Trump is the oldest person to be elected president. His father Fred was diagnosed with Alzheimer’s disease six years before his death. According to the Alzheimer’s Association, “age, family history and heredity” are the most important risk factors in developing the disease. Most sufferers start to show signs of the illness at age 65.

Remember when Trump forgot which country he’d just bombed? When it just slipped his mind to sign a pair of executive orders during an event created for that explicit purpose? When he couldn’t locate Rudy Giuliani, who was sitting directly across from him at a media briefing? Those things don’t seem like innocuous senior moments.

Trump also seems to exhibit other signs of Alzheimer's listed by health organizations. Moodiness, paranoia, belligerence and erratic behavior are all key indicators of the onset of dementia. Trump’s inappropriate tweets, his belief that his phones are tapped and his quickness to anger, as described by his staff, all fit the bill.

“I'm not saying that Donald Trump has dementia,” Joe Scarborough said during a recent segment on Trump’s mental state, “but my mother has dementia. She lives in the moment. She forgets what she said a day ago, a week ago. We can't have presidents that do that. And I'm not saying that he has dementia. I will leave that to his physician to figure that out.”

“Donald Trump is the poster boy for Alzheimer’s disease,” former NFL player and medical marijuana proponent Kyle Turley said weeks after Trump’s inauguration. “He has early onset of Alzheimer’s disease. And it is starting to show."

"What he’s doing is totally erratic," Turley added. "His decisions and the way he talks and the way he speaks is not presidential. And I want more than anything for him to do that.”