Free speech and academic freedom are endangered species on American college and university campuses. Speech codes, trigger warnings, the heckler’s veto and politically correct inquisitions have become the norm.

While there are many causes for this, the main culprit is Title IX, a federal statute enacted in 1972 that prohibits discrimination on the basis of sex in any federally funded education program or activity.

Title IX goes beyond merely prohibiting sex discrimination; it also requires that schools take proactive measures to eliminate any such discrimination.

Originally, the most visible effect of Title IX was a reduction in the number of scholarships given to participants in low-revenue men’s sports such as wrestling and baseball — or, in some cases, elimination of those sports altogether — and an increase in women’s athletic scholarships. The idea was to achieve parity, with the ratio of student-athletes in the school’s intercollegiate athletic programs mirroring the male-female ratio of the school’s undergraduate population as a whole.

In 2011, the Obama administration promulgated additional Title IX guidelines to eliminate “hostile environments” and defining sexual harassment as “any unwelcome conduct of a sexual nature.” Schools were instructed to use a “preponderance of the evidence” standard in adjudicating sexual harassment complaints rather than more vigorous standards, such as “clear and convincing” evidence or establishing guilt “beyond a reasonable doubt.” An epidemic of sexual harassment complaints was thus born.

The lunacy of the “investigations” and kangaroo courts that have resulted was exposed earlier this year when feminist Laura Kipnis, a Northwestern University film professor, wrote an article in the Chronicle of Higher Education criticizing Title IX regulations for creating an atmosphere of paranoia on campus. For her efforts, Ms. Kipnis was rewarded with a Title IX investigation, with student activists claiming that her complaints about Title IX amounted to a violation of Title IX. Ms. Kipnis was eventually acquitted by the school’s tribunal.

Broad speech codes banning free speech and anti-harassment policies are being enacted across the country, with proponents claiming that Title IX requires them.

These codes go far beyond sex discrimination. Southwest Minnesota State University, for example, bans “cultural intolerance,” which is defined as “any verbal or physical contact directed at an individual or group such as racial slurs, jokes, or other behaviors that demean or belittle a person’s race, color, gender preference, national origin, culture, history or disability.” Thus, a dirty joke, a lecture questioning the propriety of affirmative action, or criticism of the Supreme Court’s gay marriage decision are likely prohibited by the code.

Also troubling are the attitudes of America’s young adults to speech restrictions. A survey by the Pew Research Center, released last month, found that 40 percent of all young American adults said the government should censor “offensive” speech. I find that offensive.

The academic grievance industry that Title IX spawned sends the wrong message about the values that should govern a free society—let alone our universities, which are supposed to be our most freewheeling marketplaces of ideas.

The sad truth is that too many university professors and administrators like Title IX and other questionable federal mandates because it creates grievance-based jobs and fiefdoms and gives them legal cover to pass speech codes and regulations that otherwise couldn’t be justified.

What is going on today on U.S. college campuses is inconsistent with the American tradition, academic freedom and the First Amendment.

In its 1989 decision in Texas v. Johnson, the Supreme Court declared that “if there is a bedrock principle underlying the First Amendment, it is that the government may not prohibit the expression of an idea simply because society finds the idea offensive or disagreeable.” But that is exactly what is happening on campuses across the nation.

“Making Title IX as strong as possible is a no-brainer,” Vice President Joe Biden has said. But he’s wrong. What really should be a no-brainer is repeal of Title IX.

This would deprive campus activists of a tool to stifle debate and discussion. It would reinvigorate college campuses as marketplaces of ideas, rather than closed societies on the Stalinist model.

Prohibiting sex discrimination is one thing. Prohibiting free speech is quite another — and it shouldn’t be tolerated.