(Madalyn Ruggiero/AP Photo)

Vice President Joe Biden will elevate Medicare as a central issue in the 2012 campaign today with a speech accusing the Republican presidential candidates of wanting to "dismantle" it.

"Make no mistake," Biden will tell an audience of retirees at an event in Coconut Creek, Fla., "if Republicans in Congress and their amen corner of Romney, Santorum and Gingrich get their hands on the White House, they will end Medicare as we know it."

The remarks, advance excerpts of which were provided by the Obama campaign, portray Republicans as willing to extend tax breaks to the wealthy at the expense of benefits for seniors and the needy.

House Republicans earlier this week unveiled their latest budget blueprint, drafted by budget committee chairman Rep. Paul Ryan of Wisconsin, which includes deep spending cuts, controversial changes to Medicare and cuts in income tax rates.   Ryan has said the GOP presidential nominees are all supportive of his plan.

That's of little consequence to Biden.

"So, let's cut through it and say it in plain English," Biden will say of the Republican proposal to "cut, cap and balance" the federal budget.

"The 'cut' is cutting Social Security. The 'cap' is putting a cap on what we ask the wealthiest Americans to pay in taxes. And the 'balance' is balancing the budget on the backs of seniors and middle-class Americans," he says.

Ryan said this week that, contrary to Democrats' doomsday portrayals, the budget proposal will appeal to voters in the fall because of its bold attempt to reduce the national debt.

"The president and his party are ignoring this problem," he said.  "And if we have a debt crisis, the people that get hurt the first and the worst are the poor and the elderly. We will be cutting indiscriminately just like they are doing in Greece. We have a moral and legal obligation to budget, to show how we will prevent this crisis -this most predictable crisis - from coming."

Biden's campaign speech is the second of four planned to frame the 2012 election as a series of stark choices on key issues, rather than a referendum on the Obama administration's record.  He spoke to autoworkers in Toledo, Ohio, last week about Obama's support for the 2009 industry bailout and the manufacturing sector.