Paul Ryan apparently does not like operating in the realm of facts

"The Romney tax plan is premised on a mathematical impossibility. It promises to reduce tax rates by 20 percent and cover the lost revenue by eliminating tax deductions, exempting tax breaks for investment income. Even making a series of assumptions ranging from friendly to impossibly friendly, it can’t add up. The lost revenue from the tax rate cuts on income over $250,000 exceeds the available revenue from eliminating deductions. Even Republican attempts to disprove this finding have inadvertently confirmed it."

The Paul Ryan Legend Dissipates (New York Magazine)