The best argument for Congress to pass President Donald Trump's tweaked version of the North American Free Trade Agreement is also the worst argument for it.
It's the argument from stability. It concedes that the new agreement, labeled the U.S.-Mexico-Canada Agreement (USMCA), may not be a vast improvement over NAFTA, or an improvement at all. But it urges passage on the ground that otherwise we might end up with no trade agreement at all, because Trump has been threatening to withdraw from NAFTA.
This is the argument that the editors of the Washington Post are making. They have no illusions about the USMCA.