>>>Teachers unions and tenure have produced a whole crop of bad teachers, and those bad teachers can't be fired, so they have to go somewhere.
>>
>>Did teacher's unions create these conditions unilaterally?
>>As I recall, most contracts require the agreement of more than one party.
>
>Not unilaterally of course.
>The unions negotiate in effect with the same politicians the unions support.

Not so in NY and NJ.
Don't know about other states but in NY and NJ they negotiate with locally elected school boards.
As far as I know, no union official, even in NJ, has ever put a gun to the head of a school board member and forced him to sign a contract.