Lets assume that the US has a voucher system tomorrow and use some ballpark figures for the value of the voucher, say $10K per student.
Seems plausible that private schools should be able to borrow what they need to build the schools given that plenty would likely choose to use their voucher to use a private school.
Lets say that half the students currently attending govt schools choose to leave. Now the cost per student in a govt schools would be $20K per student and so the voucher would then be worth %20K, so even more would choose to move to a private school. But due to tenure, the govt teachers cant be sacked and the other costs of the govt schools still have to be paid.
Where is all that extra money going out in vouchers going to come from ?
It's just another mindless simplistic scheme that those with even the most basic education in arithmetic can see the problem with. Corse its not surprising that you lot with such lousy schools can't do simple arithmetic.