In his attempt to denigrate Paul Ryan, we see just how much of a partisan hack he can be.
Megan McArdle wades through Krugman's claims and finds them wanting.
The Tax Policy Center, while arguing the Ryan's plan needs tweaking, fends off Krugman's assertions.
The worst part of Krugman's piece - worse than his factual misunderstanding of the process for scoring tax-related legislation, worse than his idea that government spending is sacrosanct - is his tone. He's flat out snooty, mean-spirited, ad hominem, and unhelpful.
That sort of approach wasn't even necessary to make his point. His numerical assertions alone had enough heft to lead a reader to investigate further and at least question one thrust of Ryan's effort.
Likewise, the Tax Policy Center's debt forecast numbers alone are enough to make me appreciate Ryan's efforts at a Roadmap, even if imperfect, all the more:
CBO estimates that his plan would result in a debt to gross domestic product ratio (GDP) of 69 percent in 2020, rising to 99 percent in 2040, and then decreasing to 77 percent in 2060. This is in contrast to CBO's estimates for its alternative fiscal scenario (which assumes a continuation of current policy) where the debt-to-GDP ratio is 87 percent in 2020, and then rises sharply to 223 percent in 2040 and 433 (!) percent in 2060.