The leader of the free world spends four to eight hours a day glued to the television, and sucking down Diet Cokes.

He’s not the only angry old man who acts like that. You’ve probably got a surly loner uncle who has a similar routine.

During holiday visits you steer him to an empty room, plant him in front of the flat-screen and close the door, so the rest of the family can’t hear him screaming at CNN.

We can afford to humor our crazy old uncles because they’re relatively harmless. In our worst nightmares we wouldn’t picture any of them as the president of the United States, one beet-faced tantrum away from pushing the nuclear button.

But America’s cranky old Uncle Donald is in the White House, where mood-management requires the full-time attention of his jittery staff.

Russia is the touchiest subject.

Insiders familiar with the president’s daily intelligence briefings have told The Washington Post that classified information about Russian hacking and other covert activities is rarely delivered verbally to Trump for fear it will set off another rant.

Consequently, the latest intel about Russia is usually included only in the written portion of the briefings, because it is well known that president isn’t a big reader.

As disturbing and surreal as this situation might seem, there’s a comic element that practically defies satire.

Last year every U.S. intelligence agency concluded that Russian meddling in the election was real, widespread and well-orchestrated. Subsequent Congressional investigations — led by Republicans — have found the same thing.

Not a single informed person in government except crazy old Uncle Donald believes Putin’s claim that Russia didn’t interfere, culminating with the WikiLeaks release of internal emails from the Democratic National Committee.

Social media were also infiltrated to spread fake websites and blogs.

Two months ago, Google admitted that Russian state-sponsored actors posted more than 1,100 videos with 43 hours of content in a scheme to influence American voters on YouTube.

And Twitter, Trump’s favorite social platform, recently revealed that Russian operatives controlled more than 2,700 accounts and 36,000 automated bots that tweeted more than 1.4 million times during the presidential campaign.

Even more serious: In September, the Department of Homeland Security confirmed that Russian hackers attempted to breach voting data systems in 21 states, including swing states such as Florida, in advance of last fall’s elections.

We can only speculate about why Trump remains so infatuated with Putin, but we know he continually denounces the “Russia thing” as fake news meant to discredit his historic election victory.

Trump has been slightly more cautious about bashing the special counsel investigating the campaign’s contacts with Russian officials. The president’s lawyers undoubtedly have pointed out the idiocy of provoking prosecutors while one’s own son and son-in-law are at risk of indictment, so for now Trump seems to be restraining himself.

That won’t last. It never does.

Trump’s minders can edit his daily briefings, but they can’t stop him from parking in front of the television for hours at a time. He always finds something that lights his fuse and, if we’re lucky, all that happens next is a seething tweet.

That’s the difference between the president and your cranky old uncle who’s holed up in the back room, mainlining aspartame and “Fox and Friends.”

The only button your cranky old uncle can press is on the remote control.