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In a 1989 article in New Republic, Andrew Sullivan made what he called "a (conservative) case for gay marriage." Today same-sex marriage is legal everywhere in America, supported by majorities of voters and accepted as a part of American life.

Now Sullivan has cast his gaze on what he regards as a disturbing aspect of American life -- the extension of speech suppression and "identity politics" from colleges and universities into the larger society. The hothouse plants of campus mores have become invasive species undermining and crowding out the beneficent flora of the larger free democratic society.

Sullivan can be seen as a kind of undercover spy on campuses, to which he is invited often to speak -- because of his bona fides as a cultural reformer -- by those probably ignorant of the parenthetical "conservative" in his 1989 article. As Jonathan Rauch did in his 2004 book, "Gay Marriage," Sullivan argued that same-sex marriage, by including those previously excluded, would strengthen rather than undermine family values and bourgeois domesticity. That now seems to be happening.

The spread of campus values to the larger society would -- and is intended to -- have the opposite effect.

Take the proliferation of campus speech codes. Americans of a certain age have trouble believing that colleges and universities have rules banning supposedly hurtful speech. They can remember when campuses were the part of America most open to dissent. Now students are disciplined for handing out copies of the U.S. Constitution outside a tiny isolated "free speech zone."

The Foundation for Individual Rights in Education, known as FIRE, keeps a tally of campus speech restrictions and challenges codes and actions that violate the First Amendment (in public institutions) or private schools' own commitments. Its 2018 list of the 10 worst colleges for free speech includes Harvard, Northwestern, Fordham and the University of California, Berkeley.

Campus administrators have infamously declined to restrain or rebuke mobs of student "social justice warriors" who press to block conservative speakers and violently protest if they dare to appear. Examples include Charles Murray at Middlebury and Ben Shapiro at Berkeley. Students at Brown asserted that Townhall's Guy Benson isn't covered by the First Amendment.

The result, says Sullivan, is that "silence on any controversial social issue is endemic on college campuses" and, he adds ominously, "now everywhere." Last year, Google fired engineer James Damore for writing an internal memo that the CEO, with pathetic dishonesty, characterized as bigoted.

There is increasing evidence that Google, Facebook and Twitter -- whose leaders flatter themselves as enablers of free communication and neutral disseminators of information -- are suppressing conservative opinions as "fake news." Those aware of campus life will not be comforted with the knowledge that the decisions about what gets downplayed or deleted are being made by "social justice warriors" recently hired from campuses.

Corporate human resources departments are doing their part, as well. Anti-harassment rules are used to punish those uttering speech deemed politically incorrect, and actions of even the most anodyne nature are considered sexually improper.

Companies may have the legal right to do this. But their practices, amplified by bureaucratic empire building, tend to undermine what Sullivan calls "norms of liberal behavior," including "robust public debate, free from intimidation."

The campuses' encouragement of identity politics is seeping out into the wider society, too. Selective colleges and universities have long violated (and lied about violating) civil rights laws with racial quotas and preferences in admissions. And they routinely encourage blatant segregation -- separate dormitories and orientations for black students, for example.

This fosters the habit of treating individuals as, in Sullivan's words, "representatives of designated groups" rather than individuals. It assumes that everyone with a certain genetic ancestry or gender has the same views and that no one who shares that characteristic can ever understand the group -- especially someone born with "white privilege" or into "the patriarchy."

As one who has made a living for decades trying to understand the political views of people unlike me, I take umbrage. The more important points surely are that we are not prisoners of our genetic heritage and that as citizens of a democracy, it behooves us to try to understand others of all backgrounds and situations.

Sullivan is right; what is oozing out of campuses is creating a less free, less civil, less tolerant society. Can we reverse that as rapidly as -- or more rapidly than -- Sullivan, Rauch and others reversed opinion on same-sex marriage?