The more income you tax, the lower the tax rate has to be to raise the same amount of revenue. Eliminating tax breaks and loopholes is one way to do that. In fact, the recent trend has been to add tax breaks, as a way of creating incentives for such things as education and savings for retirement. So while most everyone likes the idea of broadening the tax base, doing so has turned out to be extremely difficult. But polls also show a growing number of people who say they are actually willing to pay higher taxes if governments spend the money on things that really matter, such as education and roads.
Taxation has a long and complicated history in the United States.
Resistance to unfair taxation was key to our becoming a nation in the first place.