WASHINGTON — Mixing deep cuts to safety-net programs for the poor with politically risky cost curbs for Medicare, Republicans controlling the House unveiled an election-year budget blueprint Tuesday that paints clear campaign differences with President Obama.

By attempting to focus on the budget, Republicans hope to position themselves as stepping up to a federal deficit crisis long ignored by both parties. Democrats, however, responded with promises to protect the elderly and the poor from drastic cuts they said would harm the most vulnerable Americans.

The GOP plan doesn’t have a chance of becoming law this year – the Democratic-controlled Senate has no plans to even take it up – but it provides a sharp election-season contrast to the budget released by Obama last month. His proposal would rely on tax increases on the wealthy to curb trillion-dollar-plus deficits but for the most part would leave alone key benefit programs such as Medicare.

The Republican proposal, released by House Budget Committee Chairman Paul Ryan, would wrestle the federal spending deficit to a manageable size in short order, but only by cutting Medicaid, food stamps, Pell Grants and a host of other programs that Obama and other Democrats have promised to defend.

The plan calls for steep drops in personal and corporate tax rates in exchange for clearing away hundreds of tax deductions and preferences. It would eliminate oft-criticized corporate tax boondoggles but also tax deductions and credits claimed by the poor and middle class.

To cope with the unsustainable growth of Medicare and the influx of retiring baby boomers, the GOP budget reprises a controversial approach that would switch the program – for those under 55 today – from a traditional “fee for service” framework in which the government pays doctor and hospital bills to a voucherlike “premium support” approach in which the government subsidizes purchases of health insurance.

Republicans say the new approach would force competition upon a wasteful health care system, lowering cost increases and giving seniors more options. But Democratic opponents of the idea say the proposed system would cut costs too steeply and would provide the elderly with both a shrinking menu of options and higher out-of-pocket costs. Starting in 10 years, the plan also calls for gradually raising the Medicare retirement age from 65 to 67.

“If you want to save Medicare and keep it from going bankrupt, you must reform the program, and that’s what we intend to do,” declared Ryan, R-Wis.

Mitt Romney praised the measure. “The House Republican budget rejects the out-of-control spending and higher taxes proposed by President Obama in his budget last month,” Romney said. “By proposing prescriptions that will strengthen Medicare for generations to come, it also highlights President Obama’s failed leadership on entitlement reform.”

Democrats and the White House responded with a verbal fusillade.

“House Republicans once again are trotting out their well-worn playbook to ensure that billionaires and Big Oil triumph over Grandma, Grandpa, the poor and the struggling middle class,” said Rep. Edward Markey, D-Mass. “The Republican budget scheme would end the guarantee of Medicare and force seniors to pay more out of pocket for healthcare or forgo coverage because they cannot afford it.”

For all its sweep and scope, the blueprint unveiled Tuesday isn’t actual legislation. Instead, the annual budget debate in Congress will play out on an arcane battlefield of numbers and assumptions, often difficult to understand even by Capitol Hill veterans. The budget resolution, however, sets broad parameters for follow-up legislation. Sometimes that is just a round of agency budget bills; other times lawmakers take on taxes and benefit programs like Medicare whose budgets otherwise run on autopilot.