In Washington, D.C., where I live, and in many other urban areas with troubled school systems, here is how it works for people with ambition and mobility: As they begin their careers, they live in the city for fun and convenience and dating. Then they marry and have kids. Then they look at the local public schools. Then they move to the suburbs. "I liked living in the city," my friends say. "But the schools are just so much better out here."
The strongest argument for school vouchers is moral. It is simply wrong for rich, predominantly white liberals to insist that poor, predominantly minority children attend dysfunctional and often dangerous schools that rich, predominantly white liberals would never allow their own children to set so much as one foot in. It is callous for rich, predominantly white liberals to continue to tell inner-city parents, year after year, "Urban schools must be fixed! Meanwhile, we're outta here. Good luck."
Not everyone sees the moral picture this way, of course, and so the discussion naturally turns to pragmatic considerations. The second strongest argument for vouchers is that competition would improve the performance of public schools, just as it improves the performance of people and companies and, for that matter, public universities. American higher education has long been effectively voucherized, because students can take their government loans and grants to private colleges. Not coincidentally, America's public universities are the best in the world. Vouchers would jolt public schools at first, and some would flounder and fail, but competition advocates—myself included—expect that many others would shape up and flourish with a new vigor.