In Evert's case, his group is actually a traditionalist Roman Catholic ministry. It takes anti-gay stands and makes claims that are medically inaccurate and, to be frank, ridiculous. One video on Evert's website claims that birth control pills cause abortions.

Officials at Socorro High School simply have no excuse for inviting this guy. We have this thing called the internet now, and you can use it for research. You only need about five seconds on Evert's site to see that it is chockful of right-wing Catholic dogma. (Here's how the group describes itself on its website: "Chastity Project exists to promote the virtue of chastity so that individuals can see God, and be free to love (Matt. 5:8). The orange and green colors of the Chastity Project logo are from the tilma of Our Lady of Guadalupe, to whom the ministry is consecrated."

Here's what the site says about homosexuality: "The Church recognizes that Jesus' teaching on marriage can be a cause of suffering for those who desire to live otherwise. But by upholding God's original plan for marriage, the Church is not expressing hatred toward any group of people. Rather, the Church believes that although some things in the Gospel are difficult to accept, we will only find fulfillment by trusting in God's plan for our lives."

Elsewhere it adds, "When a man and woman make love, they are renewing their wedding vows and promises with their bodies. Such a concept is easy to understand when you consider the essence of marriage. For a valid marriage to take place, the union must be free, total, faithful, and ordered toward procreation."

Parents of LGBT students at the school might have some concerns about that.

Evert claims that his presentations are secular. Call me skeptical. I can tell you how this game usually works: Speakers offer an ostensibly secular talk but spend an inordinate amount of time promoting a website or an event off campus that is anything but non-religious. Students are funneled to these venues in the hope that they'll be exposed to sectarian content there.

I've seen this scenario unfold hundreds of times in public schools over the years. Evert is a little unusual in that he comes from the Catholic tradition. Usually these hucksters are fundamentalist Protestants. We call them "pizza evangelists" because they spend most of their time in the public school urging kids to attend a "party" that night at a local church with free pizza as a lure. Of course, no one gets a bite until they sit through a sermon.

And what about the content of the talk at the school? If Evert's website is any indication, it will be next to useless. These speakers usually stress a fear-based model of human sexuality - that is, trying to scare teens into not having sex. It doesn't work.

Evert and his allies in the "abstinence" and "chastity" game insist that no one should have sex until marriage. That's their core message. So what percentage of Americans actually follow that advice? According to a 2006 study by the Guttmacher Institute, a national organization that advocates for reproductive health, it's 5 percent.

Reducing the teen pregnancy rate is a worthwhile goal, but lectures anchored in fundamentalist forms of religion that promote fear, shame and the propagation of outmoded gender roles don't help meet it. Studies have shown that simplistic stunts like scary lectures, rants about "purity" and abstinence pledges just don't work.

Comprehensive sex education, which stresses an abstinence message for teens but also discusses the reality of birth control, is the approach most Americans favor. Yet many political leaders resist it, and, as the experience in El Paso shows, so do many school officials.

Teens are smart enough to see through questionable presentations. Two years ago, a high school near Dallas brought in a speaker named Justin Lookadoo supposedly to talk about dating. Lookadoo made sexist comments, attacked feminism, promoted religion and advocated for traditional gender roles for men and women. Teens were soon tweeting sarcastic replies to Lookadoo's talk, and some walked out. The school ended up apologizing.

Officials at Socorro High School can avoid all of that. They have postponed Evert's "Love or Lust?" presentation for now, and they'd be wise to make that ban permanent.