WASHINGTON -- Republican vice presidential hopeful Paul Ryan will leave sizable footprints on the 2012 presidential race.

His controversial plan to overhaul the federal budget has been the chief talking point of the campaign since Mitt Romney put him on the GOP ticket last weekend.

Conservatives praise his blueprint for its aggressive attack on federal spending. But Democrats call it draconian because they say it slashes social programs for vulnerable Americans to fund big tax cuts for the wealthy.

Dubbed the “Path to Prosperity,” Ryan’s plan was passed by the House of Representatives earlier this year, but it died in the Senate. Rightly or wrongly, its newfound gravitas as the presumed template for a Mitt Romney budget plan has made it a lightning rod yet again.

“I want to the country to have the choice," Ryan said in an interview with CNBC in April. "Do you want the president’s path of a government-centered society, a path to debt and decline? Or do you want to get back to the American idea, the opportunity society with a strong safety net that is wired to getting people back to work, onto lives of self-sufficiency?"

Ryan’s allies say he keeps the safety net intact through free enterprise and federalism. His critics say he shreds it.

A group critical of the plan says that 62 percent of the $5.3 trillion in non-defense budget reductions over 10 years that it calls for comes from programs to assist low-income Americans. According to the liberal Center on Budget and Policy Priorities, many of the programs targeted for $3.3 trillion in cuts, like Medicaid, food stamps, public housing and Medicare, anchor the nation’s safety net of public assistance programs for the poor, elderly and disabled.

Programs that assist middle-class families, like Pell Grants and job training, would likely face cuts as well, according to Ryan’s plan.

“This budget is actually a very extreme proposal,” said Paul Van de Water, a senior fellow at the center. “The extent to which it would scale back virtually all the basic functions of government, including programs that are highly important to middle-income people, like Medicare, is just something that is unparalleled.”

If enacted, Ryan’s budget would dramatically reshape Medicaid, the state- and federally-funded health plan for the poor. As enrollment swells with jobless adults and their families who lost health care, Medicaid has become a huge drain on state finances, and many governors have called for the very fixes the Ryan plan incorporates.

Rather than paying a fixed share of total Medicaid spending, Ryan’s plan gives states capped amounts of federal money, or block grants, to operate and restructure their Medicaid programs with little federal oversight. With the added flexibility, many state leaders envision greater program efficiency and less waste.

If federal grants don’t keep pace with rising medical costs and enrollment increases during economic downturns, states could end up with less federal funding over time. Federal Medicaid spending would likely drop by $810 billion – roughly 22 percent – from 2013 to 2022 under Ryan’s plan.

Funding in 2022 alone would be more than a third less under Ryan’s budget than states would get under the current funding formula, the Center on Budget and Policy Priorities estimates.