It’s a potentially historic day. The White House has confirmed that President Trump’s campaign threat to slap tariffs on Canada, Mexico and China will become reality some time today. … Gov. Maura Healey is warning this morning, as the Herald reports, that the tariffs will lead to higher prices in Massachusetts. And they inevitably will lead to higher prices, if kept in place for a while. … But I wonder how long they’ll stay in place. I sense a declare-victory-and-get-out stunt coming, tied to very flimsy evidence of success. … And notice how the White House is tying the tariffs to “illegal fentanyl” flowing into the U.S., not other products. They’re applying a hard-to-disprove metric to all of this.