Republican presidential candidate Marco Rubio struggled on Sunday to answer a question from Fox News about whether President George W. Bush's invasion of Iraq had been a mistake.

On Sunday's edition of Fox & Friends, host Chris Wallace noted that likely GOP candidate Jeb Bush had spent much of the week trying to recover after he told Fox News host Megyn Kelly that that he "would have" invaded Iraq knowing that the country did not have weapons of mass destruction. He later insisted that he misheard the question. After evolving his answer over several days, the possible candidate eventually relented, saying, "I would not have gone into Iraq."

But Rubio seemingly missed the lesson Jeb had learned after a week of damage control.

"It was not a mistake," Rubio told Wallace.

Wallace reminded the candidate, however, that the question was "based on what we know now."

"Well, based on what we know now, I would not have thought Manny Pacquiao was going to beat [Floyd Mayweather] in that fight a few weeks ago," Rubio snarked. "The question was whether it was a mistake, and my answer is, it's not a mistake. I still say it was not a mistake because the president was presented with intelligence that said Iraq had weapons of mass destruction, it was governed by a man who had committed atrocities in the past with weapons of mass destruction."

"But what [Megyn Kelly] asked was, 'Was it a mistake to go to war with Iraq?'" Wallace pressed.

"That's not the same question," Rubio replied. "The question I was asked was what you know now."

"But that's the question I'm asking you," Wallace explained. "Was it a mistake to go into Iraq?"

"It was not a mistake for the president to decide to go into Iraq because at the time he was told..." Rubio said before being interrupted.

"I'm not asking you that," Wallace reminded him.

"The world is a better place because Saddam Hussein is not there," the Florida Republican argued. "But I don't understand the question you're asking... A president cannot make a decision knowing what someone might know in the future."

"That's what I'm asking you," Wallace tried again. "Was it a mistake."

According to Rubio, President George W. Bush "wasn't dealing with a Nobel Peace Prize winner, he was dealing with Saddam Hussein. And he made the right decision based on the information he had at that time."

"We've learned subsequently that information was wrong," Rubio added. "My answer was, well, at the time, if it had been apparent that the intelligence was wrong, I don't think George Bush would have moved forward on the invasion."

But what viewers of Fox News Sunday never learned was the answer to Wallace's question: Does Rubio think the invasion of Iraq a "mistake"?