Employers do have a right to discriminate and do so all the time.
They're just not allowed to (legally) discriminate based on race, gender, religion, and I think one or two more.
But they can certainly discriminate based on intelligence, personality, relocation, and even your favorite sports team or rock band.
And employers can and should discriminate based on how fuckin' stupid a candidate is.
take a look around here.
99% of the posters here shouldn't be allowed to carry a bucket of shit without a supervisor in tow. I'd consider it an act of compassion to keep them out of the work place.