Putting the 'Federal' Back in Federalist

I have zero idea about the legalities or environmental wisdom of yesterday's 8-1 Supreme Court ruling that Southern California's Air Quality Management District went too far in imposing strict emissions standards on vehicles, but this quote from Justice Scalia's opinion (as flagged by L.A. Times columnist Steve Lopez) is a laff riot:

[I]f one state or political subdivision may enact such rules, then so may any other; and the end result would undo Congress' carefully calibrated regulatory scheme.

Italics mine, to emphasize humor.