1.   A Johnson victory would prove that school vouchers can make good politics as well as good sense, and encourage other Republicans to campaign on them.

2.   But if school vouchers made low-cost private schooling more available, this concentration would be diluted, as students in public and private schools became more similar.

3.   But vouchers make it more difficult by draining money from them.

4.   School vouchers make a big difference for black students.

5.   Vouchers make competition.