A normal Republican Party would seize the opportunity to put a long-term limit on the growth of government. It would seize the opportunity to put the country on a sound fiscal footing. It would seize the opportunity to do these things without putting any real crimp in economic growth.
The party is not being asked to raise marginal tax rates in a way that might pervert incentives. On the contrary, Republicans are merely being asked to close loopholes and eliminate tax expenditures that are themselves distortionary.
This, as I say, is the mother of all no-brainers.
More here. Megan McArdle comments here and here.