2020 is suddenly becoming the Dementia Campaign.

President Donald Trump’s own public blunders—saying that his father was born in Germany when it was really his grandfather or referring to Apple CEO Tim Cook as “Tim Apple”—have prompted commentary throughout his term questioning whether his cognitive faculties are deteriorating.

Now that the 77-year-old Biden is the Democratic frontrunner over the 78-year-old Bernie Sanders to take on the 73-year-old Trump, questions about age-related infirmity are taking on a new volume and centrality.

President Donald Trump. | Win McNamee/Getty Images

The debate reflects the raucous, attack-oriented character of modern political culture. Genuine concerns about the capacities of people who want the world’s most powerful job mingle bizarrely with insults, jokes and self-confident pronouncements from people with no evident qualifications to be speculating publicly about other people’s neurological health.

As highlighted by Carlson’s comments—one example among many from commentators in recent days—a subject that in a previous era would be in no way a laughing matter is being treated in this era as in many ways a laughing matter.

Trump—seemingly indifferent to the glass-houses maxim—in recent days has upped the ante in what is becoming the senility sweepstakes.

On Monday, he said if Biden is elected, “They are going to put him in a home and other people are going to be running the country.” At a “town hall” on Fox on Thursday, Trump cited verbal stumbles by Biden and asserted, “There’s something going on there.” Friday morning on Twitter, he said Biden would destroy Medicare and Social Security “and not even know he’s doing it.”

Concerns about the physical and mental frailties of older presidents are far from a new phenomenon. Ronald Reagan faced questions about potential mental decline in 1984, when in a general election debate, he recited an anecdote that wandered off to nowhere, a full decade before he announced he had Alzheimer’s disease. Dwight Eisenhower in 1955 suffered a massive heart attack that sidelined him for weeks. Eager to show that they were not repeating deceptions of declining health that marked the late presidencies of Woodrow Wilson and Franklin D. Roosevelt, Ike’s physicians gave medical updates that included reports of his bowel movements.

But discussions of presidential health in those earlier times were made with a kind of hushed solemnity that now seems eons away. Modern media often takes the sort of conversations that political operatives and reporters have always had and loudly amplifies them for a mass audience.

In the cases of Biden and Trump, as their public appearances often vary widely in crispness and command of detail, the reporter-operative conversation increasingly sounds something like the way family members discuss an elderly relative, trying to distinguish normal aging from something more troubling.

“I’m becoming worried: Dad really seemed lost at dinner.” “No, no, that’s just because all the ambient noise makes it hard for him to hear. One on one, he’s as sharp as you or me.” “I don’t know, Sis, I don’t think you are facing facts.” “Oh, so now this is about me?!”

Even in his early days in the Senate, where he arrived at 30 in 1972, Biden was known for a garrulous and sometimes discursive style. In the context of a presidential campaign, however, this can raise eyebrows.

At the most recent Democratic debate, in which Biden was generally praised as having a forceful performance, his answer on whether he would allow Chinese firms to build U.S. critical infrastructure was, arguably, cumulatively coherent even though many individual sentences were not: “No, I would not. And I spent more time with [Chinese leader] Xi Jinping than any world leader had by the time we left office. This is a guy who is, who doesn't have a democratic, with a small ‘D,’ bone in his body. This is a guy who is a thug, who in fact has a million Uighurs in ‘reconstruction camps,’ meaning concentration camps. This is a guy who you see what's happening right now in — in Hong Kong, and this is a guy who I was able to convince should join the international agreement at the Paris agreement because, guess what, they need to be involved. You can cooperate and you can also dictate exactly what they are, when in fact they said, ‘We're going to set up a no-fly zone, that you can't fly through our zone.’ He said, ‘What do you expect me to do?’ when I was over there. I said, ‘We're going to fly right through it.’ We flew B-1 bombers through it. We've got to make it clear. They must play by the rules. Period, period, period.”

Trump partisans eager to exploit Biden’s circuitous words may wish first to review the large anthology of Trump classics. These include the president’s remarks to the National Republican Campaign Committee last April, when he free-associated about Democrats’ promotion of alternative energy: “Hillary wanted to put up wind. Wind. If you―if you have a windmill anywhere near your house, congratulations: Your house just went down 75 percent in value. And they say the noise causes cancer. You tell me that one, OK? ‘Rrrrr, rrrrr,’ You know the thing that makes the―it’s so noisy. And of course it’s like a graveyard for birds. If you love birds, you’d never want to walk under a windmill because it’s a very sad, sad sight. It’s like a cemetery.”

He continued in this vein, then his mind moved vagrantly to North Korea negotiations before returning to windmills with a lurch by invoking a hypothetical couple who can’t watch TV because there is no wind: ”No, wind’s not so good. And you know, you have no idea how expensive it is to make those things. They’re all made in China and Germany, by the way, just in case you’re―we don’t make ’em here, essentially. We don’t make ’em here. And by the way, the carbon, and all those things flying up in the air, you know the carbon footprint? President Obama used to talk about the carbon footprint, and then he’d hop on Air Force One, a big 747 with very old engines, and he’d fly to Hawaii to play a round of golf. You tell me, the carbon footprint.”

The strangeness of these remarks got ample news coverage at the time, but not much from conservative commentators. In recent days, however, many of these people gleefully have trained fire on Biden. Examples from recent days, compiled by my colleague Rishika Dugyala, suggest at least a loosely coordinated campaign on the right.

Fox News’ Sean Hannity, who often speaks with Trump, said it is “a legitimate question” whether the former vice president has “the stamina and the strength, the mental acumen and the focus required to serve in what is the most difficult job in the world, period. … Without a doubt, Biden is struggling.” Carlson, who also speaks informally with Trump, said Biden has “clearly lost it” and “is noticeably more confused now than he was even last spring when he entered the race.” Radio host and author Ann Coulter said that “no Republican with that level of senile dementia that Biden has” could run for president because they would be savaged by the media.

The problem for “the media,” like for voters generally, is that there is no solid consensus about how to assess cognitive health, what types of medical records should be in the public domain especially for aging candidates, and no way to enforce that consensus if it existed. The issue is especially acute now that so much power in American government is held by people older than 65. While rates of dementia are going down gradually in the United States, 65 is the age at which 20 to 25 percent of people have mild cognitive impairment and 10 percent have dementia, according geriatric researcher Kenneth Langa at the University of Michigan. Six members of the Supreme Court are over 65, House Speaker Nancy Pelosi will turn 80 on March 26, and Senate Majority Leader Mitch McConnell last month turned 78.

In Trump’s case, he has often gotten lost rhetorically in precisely the same ways for which he mocks Biden. He once referred to Israeli Prime Minister Benjamin Netanyahu as “Betanyahu.” In December, more than 700 psychiatrists and other mental-health professionals submitted a petition to Congress during the impeachment inquiry warning that President Donald Trump's mental health was rapidly deteriorating. MSNBC commentator Joe Scarborough, who has known Trump for years, said comments the president made speculating that if Andrew Jackson had come later he might have prevented the Civil War reminded Scarborough of his mother’s struggles with dementia. The "Morning Joe" host also told his audience in 2018, “It's getting worse, and not a single person who works for him doesn’t know he has early signs of dementia.”

Accusations that politicians may be drifting toward non compos mentis typically can’t be divorced from political differences that don’t concern age.

Glenn Greenwald, co-founder of the Intercept and who is backing Sanders, said on Twitter: “The steadfast, willful refusal of Dem political & media elites to address what is increasingly visible to the naked eye — Biden’s serious cognitive decline — is frightening indeed, not only for what it portends for 2020 but what it says about the ease of snapping them into line.” He was responding to one of his reporters who said Biden is “sundowning.”

Matt Stoller, another voice on the left and a Sanders backer, said on Twitter: "Democratic insiders know Biden has cognitive decline issues. They joke about it. They don’t care."

In fact, a kind of ghoulish gallows humor about the issue is widespread in political circles in both parties, in part because people simply don’t see much alternative. My colleague Marc Caputo said on Twitter that a Democratic operative with presidential campaign experience described the likely 2020 race like this: “the nice old guy with Alzheimer’s against the mean old man with dementia.”