[logfromblammo]

And that doesn't even account for lexical drift. At the time, "regulate" meant to moderate, normalize, or make uniform, a sense that is more accurately captured now in the word "regularize". The clause, at the time, probably meant that Congress was to have the power to force all states follow uniform rules with respect to trade.

The intent was probably to protect other states from circumstances wherein California could determine the emissions requirements of their cars and Texas could determine the content of their textbooks.

The clause, as intended, would have allowed the Uniform Commercial Code to be federal law instead of identical legislation passed by all 50 states. But it would not have allowed for the aforementioned political expediency.