Mitt Romney's top adviser Eric Fehrnstrom had just one question to ask of Senate Majority Leader Harry Reid following the latter's charge that the presumptive Republican nominee didn't pay taxes for 10 years: "Have you no decency, sir?"

"I don't think there is anything behind it. He hasn't produced any evidence," Fehrnstrom said Thursday in an interview with Fox News. "I'm telling you speaking on behalf of the governor that those charges are untrue, they are baseless and there is nothing to back them up."

"This reminds me of the McCarthy hearings back in the 1950s," he added.

Fehrnstrom's line, "Have you no decency, sir?" is a paraphrase of what Army lawyer Joseph N. Welch asked Sen. Joseph R. McCarthy in 1954, when he famously stood up to the powerful, witch-hunting senator who was falsely accusing people of being Communists.

In recent days, Reid has stood by his claim, made in an interview with The Huffington Post, that a Bain Capital investor told him Romney paid no taxes for a decade.

"So, the word’s out that he hasn’t paid any taxes for 10 years. Let him prove that he has paid taxes, because he hasn’t,” Reid said in a Senate floor speech Thursday. “We already know from one partial tax return that he gave us, he has money hidden in Bermuda, the Cayman Islands and a Swiss banking account. Mitt Romney makes more money in a single day than the average middle-class family makes in two years or more.”

The Senate Majority Leader also defended himself against accusations that he was spreading false attacks based on an anonymous source, telling Nevada reporters in a Wednesday conference call, "I am not basing this on some figment of my imagination. I have had a number of people tell me that."

While Reid's allegations have garnered significant attention this week, they are not entirely new -- he originally floated the same idea during a little-noticed Senate floor speech in mid-July. But his comments in the interview with HuffPost resulted in a renewed focus on Romney's taxes, ramping up the pressure on the former Massachusetts governor to release more past returns.

Also on HuffPost:

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  • Ron Paul

    "Politically, I think that would help him," Paul said in a interview with <a href="http://www.politico.com/news/stories/0712/78599.html#ixzz20w7ycTBE" target="_hplink">Politico</a>. "In the scheme of things politically, you know, it looks like releasing tax returns is what the people want."

  • Richard Lugar

    "I have no idea on why he has restricted the number to this point," <a href="http://www.cbsnews.com/8301-18563_162-57474352/pressure-mounts-on-mitt-romney-to-release-more-tax-returns/?tag=socsh" target="_hplink">Lugar said</a>.

  • George Will

    "I don't know why... he didn't get all of this out and tidy up some of his offshore accounts and all the rest," Will said on ABC's "<a href="http://www.huffingtonpost.com/2012/07/15/george-will-mitt-romney-bain_n_1674513.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+HP%2FPolitics+(Politics+on+The+Huffington+Post)" target="_hplink">This Week</a>." "He's done nothing illegal, nothing unseemly, nothing improper, but lots that's impolitic."

  • Bill Kristol

    "He should release the tax returns tomorrow. It's crazy," Kristol said on "<a href="http://www.huffingtonpost.com/2012/07/15/mitt-romney-tax-returns_n_1674325.html" target="_hplink">Fox News Sunday</a>." "You gotta release six, eight, 10 years of back tax returns. Take the hit for a day or two."

  • Robert Bentley

    "I just believe in total transparency," Bentley told <a href="http://abcnews.go.com/blogs/politics/2012/07/gop-governor-calls-on-mitt-romney-to-release-additional-tax-returns-and-show-he-has-nothing-to-hide/" target="_hplink">ABC News</a>. "In fact, I was asked today that question -- do you think that Governor Romney should release his tax returns? And I said I do. I said, I release my tax returns. I may be the only public official in Alabama that does, but I release mine every year and I just believe that people should release their tax returns. And if you get them out and just get past that, it just makes it so much easier."

  • Haley Barbour

    When asked on "<a href="http://www.nationaljournal.com/2012-presidential-campaign/barbour-romney-should-release-more-tax-returns-20120710" target="_hplink">The Situation Room</a>" if Romney should release more returns, Barbour said, "I would. But should it be an issue in the campaign? I don't think it amounts to diddly."

  • Michael Steele

    "If there's nothing there, there's no 'there' there, don't create a there,'" Steele said on MSNBC.

  • David Frum

    "Tax returns the next problem. Releasing returns under pressure: more weakness, more pain," Frum <a href="https://twitter.com/davidfrum/status/224509505973661696" target="_hplink">tweeted</a>.