Mining states congressmen have always opposed eliminating the penny. I vaguely remember reading years ago that at one time 1/3 of produced copper went into pennies. And most stores certainly like to get the extra cent.
Has anyone ever considered the number of times a penny changes hands before it wears to a slick nubbin? In utility dollars, it is well worth the cost of minting. It isn't like they were a consumable (except perhaps in the case of three-year-olds.)