Sometimes, you wake up with the feeling that it's going to be a good day. You don't know why, exactly; it's just a sense.

Sen. Joni Ernst (R-Iowa) had a similar feeling about the United States-Mexico-Canada Agreement (USMCA), the NAFTA update President Trump announced on Monday. She's absolutely confident the deal will be a wild success, even if she doesn't know why.

Ernst told CBS on Tuesday that USMCA is a "great win for Iowa." She said it would expand opportunities for the state to trade dairy products with neighboring nations and "level the playing field for wheat, as well."

"Can you explain how it does that?" asked CBS News reporter Norah O'Donnell. Ernst could not.