McDonalds is one of those class signifiers. For all its faults, it's one of America's great democratic institutions. And that photo of Trump waving from the drive-through window in his apron was like something out of Norman Rockwell. America has a graduate cultural elite that's educated itself out of understanding its own culture.
There was another great example in Trump's first term, I think in the NYT magazine, where they interviewed some posh Manhattan socialites who used to have Ivanka in their social circle, but had cut her off since her dad went into politics. I think the article was meant to portray the posh debutantes as #Resistance heroines, but it really just made them look like snooty bitches and Ivanka look cool and relatable.
I suppose the UK equivalent in humour terms would be something like Carry On. I always describe Carry On as vernacular British culture, because you can't make it upmarket or intellectual, but it pulled in enormous audiences for decades. Brits who are too sophisticated to understand its appeal are too sophisticated to understand about 80% of the country's population.