The social justice left and the reactionary right have never been at each other's throats more viciously than today. Antifa warriors and alt-right foot soldiers attack each other at rallies, clash on campuses, and see each other as mortal enemies.

But the weird thing is that when it comes to issues, their standard bearers, Bernie Sanders and President Trump, have never been closer together.

The latest proof of this came just last week when Trump unloaded against the billionaire Koch brothers on Twitter. The Kochs are free-market libertarians who have been aghast at the protectionist, restrictionist, and racist turn of the GOP under Trump. At a recent summit they indicated they would actively bankroll Democratic candidates who share their values during the midterms. (Full disclosure: David Koch sits on the board of Reason Foundation, my employer.)

Trump went ballistic. He fired off a series of tweets accusing the Kochs of being a "total joke" and "globalists" who oppose "Strong Borders and Powerful Trade" because, unlike him, they don't put "America and American workers" first.

This may sound nuts, but consider what Sanders told Vox's Ezra Klein three years ago when asked whether he would support "sharply increasing" the level of immigration to help alleviate world poverty. Without batting an eye, Sanders dismissed that as a Koch-backed "open borders" idea that would "bring in all kinds of people" who would "work for $2 or $3 an hour" and "make everybody in America poorer." Indeed, he maintained, if you believe in something "called the United States or U.K. or Denmark," then "you have an obligation ... to do everything to help poor people ... raise wages in the country."

That a high-minded altruist like Sanders who is supposed to appeal to our better angels is demonizing his intellectual opponents and echoing Trump's crass nationalism is remarkable enough. But what's even more astonishing is the fact that Sanders is supposed to be the thinking man's liberal — in contrast to Trump, who is allegedly the low-information voter's conservative who panders to our base instincts. Yet he, like Trump, is ignoring the widespread academic consensus that the harm to wages and employment from immigration is small, targeted, and short-lived while the gains are enormous, widespread, and enduring. Indeed, America's entire history shows that immigration does not harm natives, it helps them; it creates jobs, boosts real wages, and even strengthens old-age entitlement programs.

These two white septuagenarians from New York are not only simpatico on immigration but also on trade. They both scoff at the notion that free trade has raised real living standards for Americans by putting untold riches in the hands of working-class Americans, especially those who shop at the likes of Walmart, which sources cheap goods from China and Bangladesh. They have both derided NAFTA as a "disaster" for American workers and were implacably opposed to normalizing trade ties with China. But what's interesting is not just the convergence of the duo's trade views but also their rhetoric. Trump has embraced Sanders' vocabulary of "fair trade" as he smashes the international trading regime in the name of negotiating better deals. And Sanders intones darkly about the loss of U.S. "sovereignty" in "giving [foreign] corporations the right to challenge our laws before international tribunals."

And then there is their shared disdain for fiscal responsibility. Neither has any use for austerity or trimming entitlement spending — which already consumes fully three-fourths of the federal budget and is on track to consume all of it in a few decades — while cranking up infrastructure spending. And for all of Trump's assaults on ObamaCare, he is quite enamored with the idea of single payer — or Medicare for all, as Sanders calls it. The only reason he might have desisted from moving towards it right now is that liberals won't work for his administration and the conservatives he hires have no appetite for it.

Both have also lambasted the pernicious influence of money in politics — the revolving door between Wall Street and government — that allows rich guys to buy politicians and policies. Trump, of course, told voters that he was uniquely qualified to "drain the swamp" because being rich enough to self-finance his campaign meant he was beholden to no one (never mind that as a sitting president who failed to divest his business ventures he is also uniquely susceptible to self dealing by doing special favors for those who patronize his properties). Along the same lines, Sanders boasted that he was financed not by big corporations but small donations by ordinary Americans. But though Trump has proffered no real plans (besides venting) to actually prevent the moneyed classes from buying government favors, Sanders has an elaborate agenda that involves overturning Citizens United v. FEC and moving to a system of public financing where the government gives every American a fixed voucher to hand to the candidate of their choice.

But what truly unites the two — other than their hatred of Hillary Clinton — is that they love to beat up on their favorite, often overlapping, corporate villains. Besides the Kochs, both have gone after Big Pharma, Wall Street fat cats, and, most ominously, media companies. Trump has declared the "failing New York Times" and "fake news" Washington Post the "enemy of the people." He has openly fantasized about using libel laws to bankrupt his media critics and threatened to punish Washington Post owner Jeff Bezos for negative coverage by raising the postal rates for Amazon, which Bezos founded. Meanwhile, Sanders, a child of the 1960s, has his own beef with media conglomerates that he accuses of serving not the interests of ordinary Americans but shareholders. "Is there a basic conflict between making money for large media and having a serious discussion about the issues that impact the working people?" he asks. "Yeah, I think there are (sic)."

None of this is to deny that there are substantive differences between the two. Sanders' socialism couldn't be more at odds with Trump's tax cuts and deregulation. And Trump couldn't be more blasé about Sanders' crusade against global warming or his anti-law-and-order, anti-police agenda. And, stylistically, Sanders is the professor offering systemic critiques — Trump the street fighter dishing dirt.

Yet there is much uniting them, which is why fully 12 percent of voters who "felt the Bern" defected to Trump in the general election. Trump's Trumpism and Sanders' socialism are yin and yang, two sides of the same statist coin. They believe they can use the government's muscle to reverse America's decline by going after their preferred scapegoats: rich people first and foreigners second, in Sanders' case — foreigners first and rich people second, in Trump's case.

They'll both take the country down similar paths of parochialism, insularity, and internecine warfare.