MIAMI (Reuters) - Republican presidential nominee John McCain said on Friday an Ohio man dubbed “Joe the Plumber,” who raised questions about Democrat Barack Obama’s tax plan, was being smeared by Democratic attacks.

McCain spent the day campaigning in Florida, trying to fend off a strong challenge from Obama in a state the Republicans have taken in the last two presidential elections but is up for grabs on November 4.

Obama was in Roanoke, Virginia, a traditionally Republican state that is also tilting more Democratic this year. The Illinois senator attacked McCain’s health care plan.

Leading national opinion polls and surveys in key battleground states, Obama picked up the endorsements of The Washington Post and The Los Angeles Times.

The Post said both Obama and McCain are “unusually talented and qualified” candidates, but it questioned McCain’s choice of Alaska Gov. Sarah Palin as his vice presidential running mate because she is “not ready to be president.”

Speaking at a lively rally in Miami, McCain said Joe Wurzelbacher, of Holland, Ohio, was being punished for asking Obama a legitimate question.

“Last weekend, Sen. Obama showed up in Joe’s driveway to ask for his vote, and you know what Joe did? He asked Senator Obama a tough question. I’m glad he did; I think Senator Obama could use a few more tough questions,” McCain said.

“He wasn’t recruited or prompted by our campaign. He just asked a question. And Americans ought to be able to ask Senator Obama tough questions without being smeared and targeted with political attacks,” he said.

Democrats have been sharply critical of Wurzelbacher in the days since “Joe the Plumber” questioned Obama’s plan to tax Americans making more than $250,000 a year.

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MCCAIN: ‘HOLD ONTO YOUR WALLET’

The tax question prompted Obama to say he wanted to “spread the wealth around,” a comment that McCain and Republicans have jumped on as a sign that the Democrat would pursue income redistribution policies if elected.

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Obama and McCain brought up Joe the Plumber more than two dozen times at a debate on Wednesday night. Wurzelbacher’s brush with fame has come at a cost. The New York Times reported that Wurzelbacher does not have a plumber’s license and owes back taxes.

The Arizona senator ridiculed Obama’s remark about spreading the wealth, saying, “When politicians talk about taking your money and spreading it around, you’d better hold onto your wallet.”

Obama, trying to blunt McCain’s appeal in retiree-haven Florida, told about 8,000 supporters that McCain’s health care proposal to give Americans a $5,000 tax credit to help pay for health insurance would require taxing health benefits, and cutting the Medicare insurance program for seniors by $882 billion.

“If you count on Medicare, it would mean fewer places to get care, and less freedom to choose your own doctors. You’ll pay more for your drugs, receive fewer services, and get lower quality care. I don’t think that’s right,” Obama said.

McCain economic adviser Doug Holtz-Eakin charged that Obama has “consistently lied” about McCain’s health care plan.

Holtz-Eakin said McCain’s tax credit “will not only shield millions of families from a tax increase, but will actually give them more dollars to invest in their health care needs.”

“The McCain plan does not tax medical expenses like the cost of a procedure or medication,” he wrote in an e-mail memo.