Nobel Prize-winning economist Paul Krugman on Sunday accused tea party-backed Sen. Ron Johnson (R-WI) of using "non-facts" to argue that earned benefits programs like Social Security and Medicare needed to be cut in order to be saved.

"Unless we do something, these programs are going broke," Johnson opined during a panel on ABC News. "When I hear people saying Social Security is solvent to the year 2035, it's not."

"In a [sic] entitlement reform package, actually bringing in revenue for those entitlement reforms, I might look at that," he added. "But the fact of the matter is that we're already having a trillion dollars in tax increases hitting us in Obamacare. They're hidden, but it's middle class... As well as the $600 billion [in a January deal to increase taxes on wealthy Americans]. That's $1.6 trillion in tax increases hitting us in the next 10 years."

"We've just run aground right there," Krugman noted. "Your facts are false. The Social Security thing -- Social Security, it has a dedicated revenue base, it has a trust fund based on that dedicated revenue base. You can't change the rules midstream and say, 'Oh well, suddenly the trust fund doesn't count.'"

Johnson interrupted with the claim that "the trust fund is a fiction, it has no value in the federal government."

"It important to realize that the facts that are being brought out here are, in fact, non-facts," Krugman pointed out.

"They're absolute facts," the Wisconsin Republican shot back.