Marco Rubio’s presidential campaign is running into an unusual problem without precedent in the post-Reagan era: his tax cut is too big. The trouble is not so much that his tax cut is substantively too big — within the context of a Republican primary, a “too-large tax cut” does not even make linguistic sense; it would be like saying “Reagan is un-good.” Rubio’s slightly different problem is that his tax cut is so gargantuan that nobody in the party actually believes it…

The supply-siders are afraid that Rubio’s plan to cut taxes for the middle class would cost too much, forcing him to “fix” his plan by curtailing his promises to rich people…

Rubio’s plan is so wildly grandiose and unrealistic that even so math-challenged a figure as Steve Moore realizes it won’t add up. One of the things you learn growing up is that winning a bet for a dollar is worth more than winning a bet for a million dollars, because no kid ever pays up a million-dollar bet. Rubio’s plan is so crazy and unrealistic it might as well be no plan at all.

—Jonathan Chait
Has Marco Rubio Finally Created a Tax Cut So Huge Republicans Don’t Like It?