House GOP pounces after Obama budget director says health mandate ‘not a tax’

House Republicans quickly pounced Wednesday after the White House's top budget official said the healthcare reform law's penalty on people who don't buy insurance isn't a tax.

Republicans argue the admission from Acting White House Budget Director Jeff Zients undermines the White House's defense of the law before the Supreme Court. Congress has broad power to impose taxes.

"That's not a tax?" Rep. Scott GarrettErnest (Scott) Scott GarrettTrump taps USTR's Gerrish as acting head of Export-Import Bank Frustrated execs clamor for action on bank nominees Manufacturers ramp up pressure on Senate to fill Ex-Im Bank board MORE (R-N.J.) asked in reference to the mandate.

"No," Zients answered, "that's not a tax."

"I just wanted to be clear on that because that's not the argument the administration is making before the Supreme Court," said Garrett.

Other Republicans immediately highlighted the exchange.

"The President’s budget director contradicts the President’s #SCOTUS case on constitutionality of his health care: law," the press office for Rep. Paul RyanPaul Davis RyanStudents arrested protesting gun violence outside Paul Ryan’s office Parkland father calls out Trump, McConnell, Ryan after Santa Fe shooting GOP revolts multiply against retiring Ryan MORE (R-Wis.) tweeted after the exchange.

In reality, the White House's legal argument is more complicated.

The administration has argued that the penalty isn't per se a tax — that would violate the president's pledge not to raise taxes on the middle class — but that the authority to impose it is derived from Congress's authority to raise taxes. The health law calls for the mandate and the penalty to start in 2014.

In filings before the Supreme Court, White House lawyers have adopted two seemingly contradictory stances, The Hill reported last year: the administration wants an immediate ruling, so it argues that the penalty shouldn't be considered a tax because federal law prescribes courts from blocking taxes before they go into effect.

When it comes to the merits of the penalty, however, the administration has argued that it is a tax.

—Erik Wasson contributed to this story.