Jay seems to think that vouchers are bad, because the good parents are the ones who make use of them, and the kids of the bad parents are worse off because the good kids, who provide a positive influence in the class room, are now gone.  I do not doubt that good kids, with good parents, can provide a positive influence on a classroom, and that all kids in the class benefit from this.  However, it can then also be said that the good kids get less from those classes than they potentially could have if they were in voucher schools, or if their parents moved to the suburbs.  In other words, in order for the bad kids to get better, the good kids have to get worse.  Jay seems to think that's acceptable.  But as Megan recently said:

How many educated people who:

a) Oppose vouchers
b) Have children who do not attend inner city public schools

would still oppose vouchers if they were the only way to get their child out of an inner city public school? How many of them would accept that their child had to be left in that school because the systemic effects of allowing their child to exit that repulsive school would be dreadful?

Respectfully, I believe the answer is "null set".

Opposing school vouchers is, for basically every single person who does so, a completely costless belief. You get the pleasure of "supporting public education"; someone else's kid, whom you will thankfully never meet, loses their future.

In other words, do we want to enforce through law a social responsibility on parents to help other people's kids at the cost of their own.  When parents who oppose vouchers voluntarily send their kids to the worst of the inner city schools for an education in order to "lift all ships", then we'll talk. Until then, I don't believe a word you say.

Update:  And she goes on even more specifically in this post, which is just excellent.  Read the whole thing.

Update II:  Wow... just wow.  I feel I can now admit that Megan McArdle is my blog crush.  I know... you probably thought it was the Ron Paul girl... but what can I say... I always went for the brainy types.