Paul Krugman accused a Republican Senator of trying to have a debate with all the wrong facts.

During a heated Roundtable discussion on “This Week with George Stephanopoulos,” the Nobel Prize-winning economist and New York Times columnist told Sen. Ron Johnson (R-WI) that he had all the wrong facts on Social Security.

“Your facts are false,” Krugman told Johnson, adding, “It’s important to realize that the facts that are being brought out here are in fact, non-facts.”

Krugman was taking issue with Johnson’s claim that the fiscal health of the Social Security program is in danger because its trust fund doesn’t really exist. Krugman argued on “This Week” that Johnson was “changing the rules midstream” by denying that Social Security has a dedicated revenue base.

Krugman has criticized Social Security detractors for making similar claims in the past. The program is funded both by the federal budget and by a law that gives it a dedicated source of revenue, according to Krugman. That means that even when the money going into the program may be less than the money it’s paying out, its fiscal health isn’t at risk because the program still has the money it needs to run.

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