Is it better to raise rates or cut loopholes? Maybe conservatives should be preferring the boost in rates. From Kevin Drum:
…which is simpler and easier, raising rates or closing loopholes? I’d say raising rates is easier, and if it’s done now it will make it harder to raise them again in the future. This means that if Democrats want to soak the rich again, they’ll have to do it via closing loopholes, which is a harder lift.
Second, there’s Coburn’s point. If you want to have any chance at all of broadening the base and lowering rates in the future, you can’t close loopholes now. You need to leave them there as bargaining chips. Tax reform will be more likely if rates are higher (making them easier to lower) and loopholes are all still intact (giving you plenty of stuff to close in return for lowering rates).