No it's not. You can either get it by birth, or by earning it.
Originally Posted by Vieux Normand
After having already gotten it, you might act in a manner which would earn you citizenship if you hadn't already gotten it, but it's not required.
Are you trying to imply that green card labour is automatically unskilled? That non american dcotors would be unskilled doctors?
Originally Posted by metarat
That non americans would be less capable of handling "important" tasks?
Yes, doing it in a hurry is a problem, but it doesn't matter where the person is from, it matters if they've got the qualifications.
It's not like they're going to head down the the mexican border and hire the first 1000 people they see.