Clayton Christensen of the Harvard Business School predicts that half of America’s colleges will die during the coming decade, due especially to competition from online coursework.

Many will pooh-pooh this dire forecast for institutions that have been so cherished a part of the nation’s culture. But Gettysburg College historian Allen Guelzo contended that the danger is palpable, and increasing, in a recent Wall Street Journal piece (behind a pay wall).

Guelzo said America’s 1,800 private colleges are especially at risk, and the smaller they are the bigger their problem. Though elite private schools boast fat endowments, offer ample scholarship aid and lure plenty of applicants, hundreds of private campuses lack these advantages.

Schools in the Northeast are especially vulnerable. In the past six years, 17 small colleges died in Massachusetts alone, and in recent months three more in New England announced closures. The ghost of Vermont’s debt-ridden Burlington College, which went under in 2016, remains in the news because financial moves by its former head, Jane Sanders, got the blame and she’s married to a would-be U.S. president.

Parents and students may protest tuition increases that exceed inflation year by year, conservatives may bemoan faculties dominated by politically correct liberals and some pundits may question the value of a college degree.

But Guelzo said the big threat is simple demographics. He projects that sagging birth rates will reduce potential college applicants by 450,000 during the 2020s. Private colleges must charge much higher tuitions than tax-supported competitors and will be hammered further if Democrats achieve “free college for all” plans that subsidize public campuses.

Obviously a big story is brewing, and religion writers will want to focus on the 247 Catholic colleges listed by the U.S. bishops’ office and the 143 conservative Protestant campuses linked to the Council for Christian Colleges & Universities. Most are four-year liberal arts institutions, but the counts include some seminaries and other specialized programs. Myriad other schools founded by “mainline” Protestants have only vestigial faith commitments and are of less religious interest.