This article is from the archive of our partner .

Paul Ryan made two promises, but he can only keep one. As Ryan finishes up the new House Republican budget before he presents it to reporters Wednesday, he's confronting a last-minute problem on Medicare, Politico's Jake Sherman and Jonathan Allen report. He's promised House Republicans that his budget will balance itself in a decade — instead of three, as his earlier budgets did. But he's also promised that his plan to turn Medicare into a voucher system wouldn't effect anyone over the age of 55. Paul Ryan simply cannot do both of those things.

Ryan "has privately been floating the idea" of privatizing Medicare for people under 56, Politico reports. Because Ryan's previous budget for the House GOP did not cut Social Security or defense spending, it did not balance until 2040. And it required huge cuts to everything else — discretionary spending would drop from 12.5 percent of GDP to 3.25 percent by 2050. But House Speaker John Boehner promised conservatives that this time, the budget would balance in 10 years. "It's not going to be that much different, except for the fact that it will balance in 10 years," Majority Whip Kevin McCarthy told Politico. But it seems like the difference between 10 years and 30 years might be a big difference. Balancing in 10 years is hard to imagine without cutting Medicare, Alan Auerbach, an economist and budget expert at the University of California, Berkeley, told Talking Points Memo's Sahil Kapur. "It is possible in terms of arithmetic," Auerbach said, "But it is also implausible." If there aren't bigger Medicare cuts, then Ryan would have to cut Social Security and defense spending.