If President-elect Donald Trump is going to make good on his promise to deliver a “golden age of America,” he will have to find a way to make marriage great again. There is no institution more essential to the prosperity of the nation and its culture than the family. Yet no institution has declined as much as marriage over the past 50 years.

From the first census through 1960, close to 80% of all households in the United States were led by a married couple. That percentage fell slightly in the 1960s and then rapidly during the 1970s. By 2010, fewer than half of all households included a married couple, and today, that percentage stands at just 45%. Marriage has receded so much that adults between 18 and 44 are now more likely to have cohabited than to have been married.