Sorry, Republicans. You can’t buy your way to more babies.

The White House is very concerned with young people’s babymaking. President Donald Trump is considering ideas like a $5,000 “baby bonus” for new moms to encourage a baby boom, a step down from an even more ambitious $5,000 child tax credit idea from Vice President JD Vance, a longtime evangelist for encouraging more kids. “I want more babies in the United States of America,” he declared in his very first public speech as vice president. “Pronatalism,” the belief that the government should directly address America’s falling birth rates, is not inherently conservative, but it’s rapidly gaining momentum in the MAGA...