Poll: He wants to be given a free ____ and do things his way.

Egghead

Rein, guys, rein

RonBee

I would say:
He wants to be given free rein to do things his way.

~R

Leo Girard

If horses would be kings!

BIGolBOB

Arein is used to control. A reign is what a king's time ruling is called.

Stuee

The result of this poll goes to show that a lot of people just repeat phrases they hear without thinking about what the phrases mean, or how they came to be.

Having said that, I suppose both could be made to work... just.