I don't think he "believes" anything at all.I don't think Trump himself even believes his tariff myths any more, but he's going to find it impossible to gaslight the entire country as the COL rises. I think the GOP is heading for a midterm bloodbath, thus the desperation to pass the "big, beautiful bill"...
I think he feels like the most powerful man on earth and in a sense he is. This is about "see, I'm in control, and you can't do anything about it! And you won't anyway without 67 Democratic senators, which is never going to happen!"
I've had family members like this that quite frankly I wanted to murder. In control of XYZ, making colossally stupid decisions, and sneering at the fact nobody could do anything to prevent it without going to jail as an outcome. Quite frankly, my ex-wife was exactly like this.