In 2015, South Carolina Sen. Lindsey Graham was not the full-throated Donald Trump supporter he has since become. Back then, he was one of a large field of candidates challenging Trump for the Republican Party nomination and was a tough critic of the businessman to boot.

Graham’s campaign never got off the ground. But during it, he produced an interesting soundbite in which he wove in his predecessor, the late South Carolina Sen. Strom Thurmond, the reformed segregationist.

In a debate, Graham tangled with former Pennsylvania Sen. Rick Santorum on immigration. Santorum is a hard-liner who was critical of undocumented Hispanic immigrants.

Graham said he had a “different take” on the issue and quipped that old, white conservatives were not producing enough children.

“Strom Thurmond had four kids after age 67,” he told Santorum. “If you’re not willing to do that, we need to come up with a new immigration system.”

The colorful oddness of Graham’s statement — as well as its presence in a little-watched debate of second-tier primary candidates — obscured a pretty important idea. Namely, that the United States is experiencing a declining birth rate, which has serious and broad implications for the nation’s long-term economic health. Bringing in new immigrants is one way to ameliorate the impending crisis.

No other presidential candidates, Democratic or Republican, picked up Graham’s theme and it has received almost no attention in the roiling debates over immigration policy. But it should.

Economists are worried about U.S. birth rates. In March, The Washington Post reported that Americans are having less sex, and 2018 was a record in the number of people, one-quarter of adults, who reported having no sex in the past year. Among reasons for the higher celibacy numbers, discovered in the General Social Survey, are an aging population and younger people having less sex because of career pursuits, marrying later and leading increasingly digital lifestyles.

Basic biology tells us the end result is fewer babies. The birth rate, as figured by number of births per 1,000 women, is at a 32-year low, reports National Public Radio.

Lower fertility rates over time can cause the economy to shrink, as certain work categories experience employee shortages and not enough new workers come in to replace older ones, NPR says. Beyond that, and even more concerning, is that eventually our country could have too many retirees relative to active workers, whose taxes help fund retirement and other entitlement programs. The entitlement system could become unsustainable.

It is a problem that afflicts nearly all developed, western countries, and some are being proactive — to the point where governments are becoming busybodies in people’s life choices, particularly those of women.

In Italy, the government launched a “Fertility Day” to promote parenthood. In Denmark, a commercial encourages people to “Do it for Denmark.” In Russia, Putin in 2017 announced the government would hand out money for people having a first child.

The United States has yet to engage in these undignified appeals, and is one of the fortunate few countries that does not have to. But only if we embrace one of our greatest gifts — the millions of immigrants who want to move here. This would mean shifting away from our current immigration policy, which is confusing, creates logjams and lately has descended into outright cruelty with family separations and inhumane treatment in detention centers.

Immigrants are younger and have more children than Americans already here.

“We should not worry about the birth rate in the United States,” sociologist Philip Cohen with the University of Maryland told NPR. “If we want to let those people come to this country, we can solve any problem you can think of related to population size.”

The fact is most men aren’t going to be like Strom Thurmond. Increasingly, and more importantly, more American women are declining the choice made by his wife, Nancy Moore Thurmond, to have multiple children. That is their right, of course.

Adding benefits like universal family leave might encourage more working families in the U.S. to have kids, but such measures and fertility campaigns could prove unable to address structural changes in demographics.

A solution to declining birth rates is right there in front of us. All that is required is for us to embrace our history as the country where immigrants go for opportunity, and shape our policies to match.

Opinion Editor Myron B. Pitts can be reached at mpitts@fayobserver.com or 910-486-3559.