At Mr. Ryan’s request, [the CBO] produced an estimate of the budget effects of his proposed spending cuts — period. It didn’t address the revenue losses from his tax cuts.
The nonpartisan Tax Policy Center has, however, stepped into the breach. Its numbers indicate that the Ryan plan would reduce revenue by almost $4 trillion over the next decade. If you add these revenue losses to the numbers The Post cites, you get a much larger deficit in 2020, roughly $1.3 trillion.

And that’s about the same as the budget office’s estimate of the 2020 deficit under the Obama administration’s plans. That is, Mr. Ryan may speak about the deficit in apocalyptic terms, but even if you believe that his proposed spending cuts are feasible — which you shouldn’t — the Roadmap wouldn’t reduce the deficit. All it would do is cut benefits for the middle class while slashing taxes on the rich.

And I do mean slash. The Tax Policy Center finds that the Ryan plan would cut taxes on the richest 1 percent of the population in half, giving them 117 percent of the plan’s total tax cuts. That’s not a misprint. Even as it slashed taxes at the top, the plan would raise taxes for 95 percent of the population.

[…]

So why have so many in Washington, especially in the news media, been taken in by this flimflam? It’s not just inability to do the math, although that’s part of it. There’s also the unwillingness of self-styled centrists to face up to the realities of the modern Republican Party; they want to pretend, in the teeth of overwhelming evidence, that there are still people in the G.O.P. making sense.