The downward spirals have begun. The combined Social Security trust funds—one for disability, one for retirement—as well as Medicare’s hospital-insurance trust fund, will begin eating into their reserves this year, according to reports released this week by the programs’ trustees. The trust funds for these safety-net programs are now projected to diminish until they are depleted. The Medicare hospital-insurance fund is projected to run dry in 2026.

In one way, this week’s announcement was surprising. Last year the trustees...