footnote
I find it distressing that the driver's license is the standard of full citizenship.
It isn't, when crossing the border to Canada.
That is to say: a driver's license alone is not sufficient proof of American citizenship to the RCMP. They ask for your birth certificate as well, if you don't have a passport.
On the other hand, you may have a point: Crossing back into the States after a prolonged stay in Canada is as simple as showing your D.L.
