What do people see in Bernie Sanders? “Nobody likes him,” Hillary Clinton said recently. And yet with the Iowa caucuses and New Hampshire primary rapidly approaching, the 78-year-old socialist senator from Vermont is at or near the top of most polls for the Democratic nomination.

Anyone relying on the mainstream press will find it hard to understand the appeal of Mr. Sanders. That’s one of many ways that Mr. Sanders resembles President Trump. The press doesn’t like him; it doesn’t even pretend to like him. The feeling is mutual.

Earlier this month, Mr. Sanders accused the Washington Post, owned by Amazon’s Jeff Bezos, of hostility related to Mr. Sanders’ views of Amazon. Mr. Trump has had similar complaints about the Post, which has been similarly hostile to Mr. Trump.

In 2015, I wrote a column calling for a Trump-Sanders ticket, noting that they were both tapping into voter frustration with politics-as-usual.

“Both are from the outer boroughs of New York City. Mr. Sanders is from Brooklyn; Mr. Trump, from Queens,” I wrote. “Both are children of immigrants. Mr. Sanders’ father was born in Poland; Mr. Trump’s mother is from Scotland. Neither candidate served in the Vietnam War.”

On trade and immigration, neither Messrs. Trump nor Sanders are globalists. Both realize that open borders have worked better for MIT and Princeton economists than for low-skilled residents of fading northern manufacturing cities.

Both Messrs. Trump and Sanders are instinctively antiwar. Mr. Sanders would cut military spending more than Mr. Trump has, and Mr. Sanders would favor a more multilateral approach to diplomacy. Both politicians have made it clear that they opposed the Iraq War and that they don’t want to be lured into anything that looks at all like a repeat.

One dynamic that works in favor of both Messrs. Trump and Sanders is that voters discount their extreme stances, figuring that they just represent opening offers that will eventually be watered down in compromises with powerful interest groups and with establishment lawmakers.

Both have simple stories to tell about who is to blame for America’s problems. Mr. Trump blames illegal immigrants, who do not vote. Mr. Sanders blames “billionaires,” who represent only a tiny fraction of the electorate (though, between Michael Bloomberg and Tom Steyer, they do represent a substantial fraction of the field of Democratic presidential candidates.)

From a policy perspective, Mr. Sanders is not at all my cup of tea. His proposed wealth tax is punitive, confiscatory, and probably unconstitutional. His health care plan and his other proposals demonstrate, in my view, naïve and unfounded confidence that centralized big-government programs can solve problems better than decentralized or private-sector initiatives.

Yet the panic that Mr. Sanders engenders in a certain class of New York and Washington types — the sort of people that Hillary Clinton is talking about when she says “Nobody likes him” — is a similar panic to the one those people feel about President Trump. Do I need to feel guilty about admitting that I not-so-secretly enjoy it?

Sure, some of the Mr. Sanders voters are holier-than-thou poseurs or outright sexists. Some of them are just naïve or ignorant, too young to have lived through the Cold War against the Union of Soviet Socialist Republics. Plenty of Sanders voters, too, are legitimately fed up.

The free-trade, easy money policies of the George W. Bush and Obama administrations didn’t work for them. They feel insecure because of immigration, the opioid epidemic, the mental health crisis, the erosion of social capital, the decline of organized religion, and the concentration of economic growth in Silicon Valley, Boston, Northern Virginia, and Seattle rather than the rest of the country.

It’s a protest vote, a cry of frustration with the status quo. It’s an “I’ve had enough and I’m not going to take it anymore” vote.

Mr. Sanders is a more credible voice of that message than is wealthy Harvard law school professor Elizabeth Warren or Mr. Obama’s vice president, Joe Biden, or Rhodes Scholar Pete Buttigieg or billionaire businessman Michael Bloomberg.

Whether Mr. Sander’s a more credible voice of it than Mr. Trump himself — or whether the feeling even accurately represents the sentiments of most Americans in a moment of relative peace and prosperity — is something that we may yet discover in a general election campaign.