But times have changed. The profile of the 435-member House – considered the junior circuit to the 100-member Senate – has risen in recent years thanks, in part, to the dramatic shift in power from Democratic to Republican control in 2010 and the influx of tea party members, and Ryan has been one of its most high-profile lawmakers.

Ryan’s budget plan is widely regarded as a blueprint for conservatives on the key issue of the day. It would repeal the 2010 federal health care law, give states more say over Medicaid and limit government spending to 20 percent of the economy by 2015 – it’s been about 24 percent.

Under Ryan’s plan, there would be just two income-tax brackets, 10 percent for low-income earners and 25 percent for higher wage earners and corporations. The current top rate is 35 percent. Ryan said lost revenue would be made up for by closing loopholes in the tax code as well as through renewed economic growth, an assertion critics say is misguided.

Ryan’s Medicare plan would have no effect on current beneficiaries. People now under 55 would be able to choose traditional Medicare or private plans when they become eligible starting in 2023. If they selected a private program, the government would provide a payment to the insurer to help subsidize the cost. Seniors could pick plans from an exchange, and each insurer would have to offer a minimum level of benefits.

Ryan has said that such a system would force plans “to compete against each other to serve the patient (and) will help ensure guaranteed affordability.” Opponents say the change would wind up costing seniors more.

Ryan’s strengths are regarded as a command of budget details and a willingness to go out on limbs that ambitious politicians rarely are willing to take on. But his resume has one flaw: He’s shown few tendencies to engage in serious work with Democrats or moderates to fashion the kind of compromise that can pass Congress. Still, even skeptics laud him for his tenacity and willingness to tackle issues that other politicians have shied away from.

“I give him enormous credit for taking on this significant issue, something the president regrettably has failed to do," said Sen. Susan Collins, R-Maine, who opposed Ryan’s budget plans.

Franco Ordonez contributed to this report from Manassas, Va.