In Florida, Biden Attacks Romney on Social Security and Medicare Campaigning in Florida, Vice President Joseph R. Biden Jr. widened his attack against Mitt Romney on Friday to accuse him of favoring higher taxes on Social Security benefits to pay for tax cuts for the rich. "Right now the majority of seniors, over 50 percent, pays zero income tax on their Social Security benefits," Mr. Biden said. Those with higher incomes pay taxes on the benefits on a sliding scale. "If Governor Romney's plan goes into effect, it can mean that every, every one of you would be paying more taxes on your Social Security," Mr. Biden said. He spoke at a retirement community in Boca Raton just a couple of miles from the home of a wealthy Republican donor where Mr. Romney uttered his remark in May about the 47 percent of Americans who feel entitled to a handout. "The average senior would have to pay $460 more in taxes for their Social Security," Mr. Biden said. The vice president earlier attacked the deficit-cutting plan of Mr. Romney and his running mate, Representative Paul D. Ryan, for transforming Medicare into a program he called "vouchercare." Sounding an alarm about Social Security is even more of a flashing red light, especially in senior-centric Florida, a battleground state in the election. In response, Ryan Williams, a spokesman for the Romney campaign, said, "Vice President Biden is using Social Security to fabricate the Obama campaign's latest false attacks." Mr. Biden's charge was based on a Democratic interpretation of an independent analysis of Mr. Romney's tax proposals that Republicans have called flawed. Mr. Romney has said that he will pay for his across-the-board cuts in income taxes and other taxes by eliminating deductions, but he has never specified which ones. The analysis, by the Tax Policy Center, concluded that making up all the revenue lost by Mr. Romney's tax cuts would require eliminating tax breaks, as Mr. Romney has said he would do, but not just for high earners. Households earning below $200,000 would lose 58 percent of their tax deductions - like the one for mortgage interest - the Tax Policy Center said. That would lead to higher total taxes for such households. The Obama-Biden campaign extrapolated from this analysis to currently untaxed Social Security benefits. It figured an average increase on these benefits of $458 per household. The campaign claimed that even senior couples with incomes of as little as $32,000 would see an increase. Mr. Williams, the Romney spokesman, said that both the original Tax Policy Center study and the Obama campaign's analysis of it were riddled with false assumptions. He pointed to Mr. Romney's campaign Web site discussion of Social Security, which says, "Mitt's proposals will not raise taxes and will not affect today's seniors or those nearing retirement." "These attacks will backfire," Mr. Williams said in a statement, when voters learn that Mr. Biden "supported higher Social Security taxes, and that seniors face a 25 percent across-the-board benefit cut because of President Obama's failure to lead on this issue." The reference was to Mr. Biden's vote on a 1993 Clinton-era budget that raised taxes, including expanding the portion of Social Security subject to income tax. An earlier version of this post incorrectly referred to Ryan Williams, a spokesman for Mitt Romney, on second reference as Mr. Ryan, not Mr. Williams.