What do these events have in common?

A deranged Bernie Sanders supporter opens fire on a group of Republican congressmen at baseball practice and would have killed them all but for the unusual presence of two Capitol Hill police officers.

A version of Shakespeare's Julius Caesar features the assassination of an actor who, instead of wearing a toga, is dressed to look like Donald Trump.

A comedienne for CNN appears ISIS-like, holding the image of Donald Trump’s severed head — dripping with fake blood.

On college campuses throughout the country black students insist on separate, black-only graduation ceremonies and at one institution black students insisted that everyone who was white leave the campus for a day.

An increasingly hostile atmosphere prevents conservative thinkers from even appearing on college campuses; and, in some cases, the resistance leads to violence, personal injury and property damage.

Since Donald Trump’s name figures prominently in each of these events, is the president to blame? Remember, Trump is not a traditional Republican or even a traditional conservative. In the past he gave money to Hillary Clinton, Chuck Schumer and other Democrats. So why are Trump’s critics going through the emotional equivalent of the St. Vitus dance?

To answer that, look at the critics, not at Trump.

Liberalism without Ideas. During the last election, Donald Trump raised a number of issues — some of which were unusual in presidential politics. Uncontrolled, illegal immigration. A changing labor market that is leaving behind blue-collar workers with no college degree. A tax system that is making us uncompetitive in world markets. An education system that is failing inner city, minority youths. Environmental policy that is preventing the construction of roads, bridges, pipelines and just about every other infrastructure project. A health reform that is self-evidently imploding.

Some of Trump’s solutions were standard Republican fare. School vouchers and a flatter, fairer tax system, for example. Most conservatives don’t think he had very good answers on some other issues, however. But here is the important question: Can you say with any confidence what Hillary Clinton proposed to do about any of these problems? I bet you can’t.

As for Bernie Sanders and the left-wing of the Democratic party, there seem to be some concrete proposals. But I can’t think of one that is different from what the left was saying back in the 1930s.

The Left in America is intellectually bankrupt. And this is a worldwide phenomenon. For most of the 20th century the ideological Left controlled the policy agenda. But in the last quarter of that century, it experienced a complete intellectual collapse. Ronald Reagan was elected. So was Margaret Thatcher. The world saw a surge in privatization and deregulation. Eastern European countries turned to the flat tax. More than 30 countries either fully or partially privatized their social security systems. Sweden adopted a national system of school vouchers.

On reflection, the Left was wrong about everything. It was wrong about communism. It was wrong about socialism. It was wrong about the welfare state. Given that history, why would it want to talk about ideas?

A Party Without Ideas. You’ve heard the old saw. Some people talk about people, while others talk about ideas. It applies here. Bereft of any credible policy proposals, politicians have little else to do but focus on identity politics. Throughout the 20th century, the Democratic Party was always the party of division. In the South, Democratic politics was the politics of race. In the North, Democratic politics was the politics of class, envy and ethnicity. Still, there were real issues at stake.

Today, identity politics is all there is. In the last election, Hillary Clinton asked women to vote for her because they are women. Blacks because they are black. Hispanics because they are Hispanics. Gays because they are gay. Her race baiting at the Democratic National Convention last year was shameless, including putting on the stage the mother of Treyvon Martin, whose death was parlayed into a fake racial incident in order to spark racial resentment and drive black voters to the polls.

This is the new racial politics and it’s been going full throttle for some time. For example, the eve of the 2000 election the NAACP ran radio and television ads trying to falsely convince black listeners that Texas Gov. George W. Bush favored leniency for three white racists who dragged a black man to death behind a pickup truck. (For more, see here, here and here.) All of this was ignored, of course, by the mainstream media.

An unfortunate consequence of identity politics is that the political becomes personal. Hillary voters tended to see her not as someone who was going to deliver the goods but as someone who would protect their personhood. That implies that the opposing candidate is a threat to their personhood.

Donald Trump campaigned for the votes of out-of-work steel workers and coal miners and blue-collar workers everywhere. But he never appealed to them based on sex or race or personal identity. He appealed to them as ordinary Americans. As political scientists Matt Grossman (Michigan State University) and David Hopkins (Boston College) point out in Asymmetric Politics, Republican and Democratic candidates campaign in very different ways.

Donald Trump may have been crude and rude and ill-considered, but there is nothing in his history to suggest he is anti-black, anti-gay or any of the other anti’s. His voting results bear that out. Palm Beach is historically considered the most discriminatory resort community in the country. When Donald Trump opened Mar-a-Lago, he ruffled more than a few feathers by welcoming everyone.

As for women, no political couple in U.S. history has been more abusive to them than Bill and Hillary Clinton. But if you think your personhood is on the line, emotion tends to trump clear thinking — no pun intended.

Campuses Without Ideas. Historically, colleges and universities in this country represented fountainheads of free inquiry. They were places where the free exchange of ideas was permitted and encouraged. Important public policy proposals historically have come from the academic world.

But no more. As I wrote in my last post, our campuses are increasingly infected by the idea that people have rights and responsibilities based on their genes. Or their ethnicity. Or their sex. Or their sexual preferences. Instead of debating whether vouchers would help liberate poor minority kids who are attending bad schools, for example, some campus protestors are claiming that even hearing the case for vouchers “marginalizes” black students. Ditto for welfare reform, or just about any other reform proposed by someone who is right-of-center.

Further, we are increasingly told that speech itself is a form of violence. So, physical violence is justified to silence speech that is “offensive.”

Anti-intellectualism is so consuming campus life that even a slight deviation from political correctness on questions of identity can provoke scathing condemnation. In one case, an assistant professor of philosophy published an article on “transracialism," comparing the choice of people of mixed race to choose to be black rather than white (or vice versa) to transgender choices. "Society,” she concluded, “should accept such an individual’s decision to change race the same way it should accept an individual’s decision to change sex.”

Unfortunately for the professor, she is white. An open letter signed by more than 800 academics called for the article to be retracted. The professor’s life hasn’t been the same since.

A Culture Without Ideas. What is happening on college campuses is a barometer of what is happening in elite culture as a whole. Writing in The New York Times, Kenan Malik reports that:

Hal Niedzviecki, editor of Write, the magazine of the Canadian Writers’ Union, penned an editorial defending the right of white authors to create characters from minority or indigenous backgrounds. Within days, a social media backlash forced him to resign. The Writers’ Union issued an apology for an article that its Equity Task Force claimed “re-entrenches the deeply racist assumptions” held about art.

Another Canadian magazine editor and an editor for CBC television were demoted for expressing similar thoughts.

There is more:

When New York’s Whitney Museum picked for its Biennial Exhibition Dana Schutz’s painting of the mutilated corpse of Emmett Till, a 14-year-old African-American murdered by two white men in Mississippi in 1955, a petition was organized to have the work destroyed because Schutz is white.

When a protest developed in response to sculptor Sam Durant’s piece “Scaffold,” honoring 38 Native Americans executed in 1862, the artist atoned by dismantling his own work, and making its wood available to be burned in a Dakota Sioux ceremony.

Then there is Hollywood. “I’ve thought a lot about blowing up the White House,” says Madonna. “I’d like to punch [Trump] in the face,” says Robert De Niro. The 15 worst examples of such intemperate rhetoric are listed at Breitbart.

Bottom line: Having lost all interest in ideas (because basically it has nothing to say) the political Left has turned to identity culture — asserting that people have rights and obligations based on their genes or their ethnicity or their gender. If you disagree with leftists, they will not debate the merits of the case. They will instead attack you as an enemy of the groups for whom politically correctness requires sympathy. And they will encourage members of those groups to lash out against you — violently in some cases — because in the world of the mindless, brute force is the only thing left.