What they should be bound to is making "temporary-but-not-really" staff, just staff. But for that, strong unions are necessary, and US unions have been very wee

What they should be bound to is making "temporary-but-not-really" staff, just staff. But for that, strong unions are necessary, and US unions have been very week for decades (especially w.r.t. rate of unionization and centralization of power away from rank-and-file workers).