Political discussions commonly assume there are two separate sets of issues.

There’s a social agenda — issues such as abortion and marriage. And there’s an economic agenda — issues such as federal spending, debt, taxes and government entitlement programs.

It’s usually assumed that these two agendas don’t have anything to do with each other.

But it’s simply false that we can consider the challenges of our federal budget without thinking about the state of the American family, our birthrates and abortion.

Three massive entitlement programs (Social Security, Medicare and Medicaid) now make up about 45 percent of the current federal budget.

These programs are overwhelmingly driven by demographics of the country — mostly directly, but also indirectly. Their economics are driven both by how long we live and how many children we have.

Social Security and Medicare focus on the elderly, to ensure they have income and health care. Because they are financed through payroll taxes of working Americans, their viability depends on how many people are working compared to the size of our aged retired populations.

This picture is changing dramatically for the worse. And this is the root of the nation’s fiscal problem.

In 1945, there were about 42 working Americans paying payroll taxes for every retiree receiving Social Security benefits. By 1960, this ratio had dropped to about 5-to1. Today, it is about 3-to-1.

Americans are living longer, but having fewer children.

Currently, about 13.3 percent of the U.S. population is over 65. The Department of Health and Human Services projects that by 2040 — in a little over 25 years — 21 percent of the U.S. population will be over 65.

Meanwhile, birthrates are dropping. Between 1920 and 1970, birthrates varied from a high of about 118 births per 1000 women of childbearing age to a low of about 80, according to data compiled by the Pew Research Center. In recent years, this rate has dropped to a little more than 60 births per 1000 women.

A report from the chief actuary of the Social Security Administration discusses factors that have led to the drop in birth rates. These include more use and availability of birth control, more women working, postponement of marriage, increased prevalence of divorce and more women choosing to remain childless.

Not surprisingly, the SSA report ignores the impact of legal abortion. But this is a critical factor. You can look at any chart showing historical fertility rates in the United States and see it bottom out after the Roe v. Wade decision in 1973 and staying around those levels.

Because fewer and fewer people are working for every retiree, our current level of taxation is nowhere near covering what the requirements for Social Security and Medicare will be soon.

Meanwhile, although Medicaid is usually thought of as health care for the poor, it’s the source of funding for most long-term care for the elderly. Today, about 60 percent of Americans in nursing homes and long-term care institutions are being covered through Medicaid.

Just think what this financial burden will look like as the elderly become an increasingly large portion of our population.

It’s why projections for the shortfalls in Social Security, Medicare and Medicaid combined have been as high as $126 trillion.

A central premise of Obamacare is forcing healthy young Americans to buy health insurance to subsidize overall premium costs for older and less healthy parts of the population. What happens as the percentage of youth in our population continues to shrink?

It should be clear that it is impossible to separate marriage, children and abortion from the nation’s overall economic picture. These so-called social issues underpin the fiscal issues.

A renaissance in American family life -- which entails a restoration of marriage and children as central to our culture -- and a purging of the scourge of abortion can restore a healthy future that today looks so ominous.

Star Parker, a Washington Examiner columnist, is an author and president of CURE, Center for Urban Renewal and Education. She can be reached at www.urbancure.org