Republican presidential candidate Mitt Romney has a response to rival Newt Gingrich's claim that he's a weak frontrunner: I know I am but what are you?

On Sunday, Gingrich told Fox News host Chris Wallace that the former Massachusetts governor had one of the most anemic campaigns in the last 100 years.

"The fact is that Romney is probably the weakest Republican frontrunner since Leonard Wood in 1920, and Wood ultimately lost on the 10th ballot," the former House Speaker asserted.

Gingrich was referring Gen. Leonard Wood, who was considered the Republican frontrunner in 1920 but eventually lost the nomination to Warren G. Harding at the convention.

"It's funny to listen to these guys," Romney told Fox News host Gretchen Carlson on Monday. "They are saying what they wish to be the case but what happens not to be the case."

"If I'm a weak frontrunner then what does that make Newt Gingrich because I'm well ahead of him?" he added.

Carlson noted that Republican presidential candidate Rick Santorum has also charged that Romney "can't close the deal."

"Oh, we're closing the deal, state by state, delegate by delegate," Romney insisted. "I've got by far the most votes among Republicans so far."

Watch this video from Fox News' Fox & Friends, broadcast March. 12, 2012.

(H/T: USA Today)