Less than an hour into the first presidential debate, Rep. Paul Ryan's (R-Wis.) budget blueprint has taken the spotlight.

"I don't think vouchers are the right way to go," President Obama said, reprising an attack line that Democrats have frequently used against the House Budget Committee chairman's plan to overhaul the popular entitlement program for the elderly and disabled.

Mitt Romney defended the Ryan plan in much the same way that Ryan himself has on the trail -- by casting it as a proposal with bipartisan roots. Romney notably declined to say, however, whether he agreed with Obama's characterization of the proposal as a "voucher" plan -- a point on which Ryan touched in his speech before the AARP in New Orleans last month.

In that speech, Ryan criticized Democrats' use of the word "voucher" as a poll-tested strategy of mobilizing the public against the plan. We're likely to hear much more on the topic in a little over a week, when Ryan and Vice President Biden face off at the vice-presidential debate in Danville, Ky.