...they can't drive...

And when did not being able to drive become a criminal offense ?

...and don't pay taxes...

Well, if you're an illegal immigrant, it seems daft to attempt to pay taxes -- the goverment would suddenly notice the extra money and wonder where it's coming from...

On the other hand, if the goverment gave these people citizenship (or working visitor status), maybe they'd be grateful enough to pay their taxes.

Disclaimer: Note that I'm not having a dig at you, but at the people "who tend to be pretty harsh towards them".