Eric Fehrnstrom, a senior adviser to Mitt Romney, admitted Monday that he actually agrees with the Obama administration on something: the individual mandate in the Affordable Care Act is a "penalty" and not a "tax."

Since the Supreme Court upheld President Barack Obama's health care law but ruled that its mandate is a tax, Republicans have criticized him for imposing a massive taxon the American public.

The Romney campaign joined in this line of attack, with an adviser telling The Huffington Post's Jon Ward that the Supreme Court's ruling would help them politically.

But in a Monday interview on MSNBC's "The Daily Rundown," Fehrnstrom contradicted this statement, agreeing with the Obama administration that the mandate is a "penalty" on individuals who do not purchase insurance -- not a tax.

The tax line is uncomfortable for Romney, whose signature health care reform legislation in Massachusetts also had an individual mandate and could therefore be construed as a tax -- a definition the presumptive GOP presidential nominee wants to avoid.