According to the American Federation for Children, Sen. Marco Rubio (R‑FL) and Rep. Todd Rokita (R‑IN) have reintroduced “the Educational Opportunities Act, which would create an individual and corporate tax credit for donations that pay for scholarships for students to attend a private school of their parents’ choice.”

It is encouraging to see growing support for scholarship tax credit school choice programs, which have been found to simultaneously boost achievement for students who switch to private schools, do the same for students who remain in public schools, and save taxpayers millions of dollars every year–a win-win-win scenario. Nevertheless, it is ill advised to pursue such a program (or other school choice programs) at the federal level.

Years ago I summarized those problems when President George W. Bush advocated creating a federal school voucher program. Such programs are not only beyond the mandate accorded to Congress by the Constitution, they bear the risk of suffocating private schools nationwide with a raft of new regulation, defeating their very purpose of increasing the range of educational options available to families with limited means.

In the past few years I have visited Sweden and Chile and studied their federal school chioce programs. Both confirm my earlier worries about national programs. Chile’s entrepreneurial voucher schools grew rapidly at first, but with a recent change of government hostile to the program they have sensed the new climate and stopped expanding.The new government is trying to enact regulations to diminish the scope and freedom of private schooling in Chile.

Meanwhile, something similar is happening in Sweden. Among other things, the government has mandated that all schools hire graduates of government-certified teacher training programs, despite the well known fact that those programs are currently attracting the lowest-achieving college students.

National school choice programs have proven to be a prime case of “staff car legislating.” The legislators who enact them are not always the ones in the official staff cars, making the rules. New lawmakers with different preferences ultimately come to power and can wreak havok on a nation’s entire K‑12 education sector.

This problem can be minimized by leaving school choice legislation to the state level, where the Constitution rightfully leaves it. We thus have a “laboratory of federalism”–a variety of different policies across states that make it easier to determine how best to design such programs.