Associated Press

The weak economy and high unemployment concern Americans the most, polls show. Yet much of the political heat generated lately has been over Medicare and Mitt Romney's tax returns.

Polls aside, neither issue seems likely to go away.

Medicare became a hot topic when the Republican presidential challenger named Rep. Paul Ryan of Wisconsin as his running mate. Ryan, who is House Budget Committee chairman, has authored conservative budgets that would slash domestic spending and revamp Medicare and Medicaid.

President Barack Obama and other Democrats have been hammering Ryan's proposals in an attempt to tie Romney more closely to them.

Romney has pushed back hard, seeking to turn the tables by insisting Obama is the one who'd wreck Medicare. The subject is important in swing states with many seniors, including Florida.

"We will lead, we will take on the tough issues," Ryan told a rally Friday in Glen Allen, Va., his first of two in Virginia.

Speaking to reporters Thursday in South Carolina, Romney used a white board to defend and contrast his Medicare stance with Obama's.

Questions quickly turned to his taxes.

Romney said he'd checked his returns for the past 10 years and "every year, I've paid at least 13 percent." Prove it, Democrats demanded.

Obama's campaign promised Friday not to demand more returns or offer further criticism "for the rest of the campaign"- if Romney would release five years' worth.

He's released only his 2010 return and an estimate for 2011, and he says there will be no more. The 2010 form showed a 13.9 percent effective rate.

Romney was fundraising Friday at in Southampton, N.Y. On Saturday, Ryan will campaign - with his mother, in her late 70s - at a retirement community in Florida, where interest in Medicare issues is keen.

Obama and Vice President Joe Biden had no scheduled campaign events.


Follow Tom Raum on Twitter: For more AP political coverage, look for the 2012 Presidential Race in AP Mobile's Big Stories section. Also follow and AP journalists covering the campaign:

Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.