Writes Dom Armentano:

Lew’s inciteful  2nd Amendment discussion makes the important point that Constitution understanding always depends upon taking account of 18th Century language and meaning.  He notes, for example,  that the phrase a “well regulated militia” meant, in the language of the Founders, a militia made “regular”, that is, made orderly; it did NOT mean that the Founders intended that the Congress could “regulate” the militia (!), as we would use the term today. No way.

Exactly the  same issue arises in a proper understanding of the Commerce Clause. The text reads that the Congress was to be vested with the power to “regulate trade among the several  states.”  But the term “regulate” in its 18th Century meaning, meant that trade was to be made  “regular”, i.e. made orderly; it did NOT mean that the Congress should “regulate” trade as we would use that term today. Indeed, the Founders intended the exact opposite, i.e., that the Commerce Clause  would insure that the states themselves did not make trade “irregular”  (as they were already doing) by imposing  tariffs and taxes and other impediments to “the free flow of commerce.”