Seniors attend a "Medicare Monday" seminar at the Holly Creek retirement community in Centennial, Colorado. (John Moore/GETTY IMAGES)

“Whenever you put bold reforms to try to fix budget problems, the other party uses it as a political weapon against you,” Rep. Paul Ryan (R-Wis.) said this morning on Bloomberg TV.

Maybe he was thinking back to the 2010 election, when Republicans used changes to Medicare against Democrats to great political effect .

Seniors broke for Republicans by a twenty-one-point margin in 2010 after being about evenly divided in 2006.

Now that Ryan, the architect of Republicans’ budget plan for the 2012 fiscal year, is proposing to essentially privatize the Medicare system in order to begin closing the massive federal deficit, will Democrats be able to turn the political tables?

Democrats acknowledge that the Medicare-focused ads worked by pushing seniors into the Republican column and blunted their own warnings of cuts to Social Security. The frequently-used attack that Democrats were cutting $500 billion from Medicare “was very effective, always tested very very well,” says Joanna Burgos, a spokeswoman for the National Republican Congressional Committee. (Here are some examples.) In 36 races where the GOP or their allies ran ads on Medicare cuts, Republicans won all but three.

According to non-partisan political handicapper Charlie Cook, party insiders are worried that the Medicare overhaul outlined in the Ryan plan, which would change Medicare for those under 55 from an entitlement program to an insurance subsidy, could jeopardize the gains the party has made with older voters over the past decade.

“Part of it depends obviously on how far it goes,” said Republican pollster Whit Ayres, pointing out that Democrats already tried to use the prospect of privatization as a wedge issue in 2010 and failed. “Change is difficult ... It depends on how effective the messengers are.”

Forty-six percent of Americans said cuts to Medicare are “totally unacceptable” in a February NBC/Wall Street Journal poll. Another 30 percent said cuts were “mostly unacceptable.” Fewer respondents, but still a majority — 53 percent — were opposed to turning Medicare into a voucher program. Among people over 65, polling shows even stronger opposition to vouchers.

Ryan says his program is not a voucher program but rather “premium support.” The government will still give people money to buy their own insurance, but the amount of money will be flexible. Republicans also argue that because the proposed changes wouldn’t affect anyone over 55, they will be protected from a senior backlash.

But debating policy details didn’t do much for Democrats last year. They tried without much success to explain that the $500 billion in Medicare savings was a reduction in the growth of spending over the next decade, not an immediate slashing of benefits. The result? A 63-seat loss in the House.

Both Democrats and Republicans agree that Medicare costs need to be reined in. Democrats managed to pass their cuts to the system, but it came at a huge political cost. Now Republicans have their own plan for keeping costs down, one they argue will save the program by keeping it out of bankruptcy. Democrats are already planning to use the Ryan budget as an attack in competitive Senate races, a leading edge of a broader focus on the issue heading into the 2012 election.