Rep. Joaquin Castro (D-TX) lashed out at House Oversight Committee Chairman Darrell Issa (R-CA) on Sunday for spending over a year on what he said was a crusade on a "fairy tale" after a New York Times report showed that Al-Qaeda had no role in the 2012 Benghazi attacks.

In an interview with NBC on Sunday, Issa was pressed about a New York Times investigation published over the weekend that revealed that Al-Qaeda did not plan or carry out the attacks at the U.S. outpost in Benghazi, undercutting the foundation of Republican arguments, hearings and accusations against President Barack Obama for the last year.

"Why use the term Al-Qaeda?" MSNBC's Andrea Mitchell asked Issa. "When you say Al-Qaeda, people think central Al-Qaeda. They don't think militias that may be inspired by [Osama bin Laden] and his other followers. So, it is a hot button for political reasons."

"But, Andrea, it was accurate," Issa insisted. "There's a group that was involved that claims an affiliation with Al-Qaeda. Now, Al-Qaeda is not a central command and control. It was, in fact, a loose group that could take general statements and act on them."

But Castro said that it was time for the chairman and other Republicans to "learn a lesson" and move on from their obsession with the Benghazi attacks.

"Chairman Issa and members of that committee crusaded for over a year on what was really a fairy tale, claiming that the administration knew that Al-Qaeda was involved and wouldn't admit it," he explained. "Some of the information that came out early, although it may have been wrong, that was their best effort."

"Darrell Issa and others took that and crusaded against the administration in a way that, I think, has been a big distraction for the American people," Castro added.