The two disagree on how to respond to Monday's lawsuit filed by the U.S. Department of Justice to block the state's tough new voter laws.
Cooper calls the governor's decision to hire an outside attorney to defend the state a waste of money. He told reporters Tuesday that he may not personally agree with the new voter laws, but his office is more than capable of defending them.
"There are laws that I have disagreed with personally that our staff have defended successfully," said Cooper.
McCrory will not allow the attorney general's office alone to defend the state against the federal lawsuit to block North Carolina's new Republican-backed voting laws.
"These lawsuits are incredibly important to the people of North Carolina," said McCrory's Chief Legal Counsel Bob Stephens. "We're going to win."
In a news conference, Stephens defended the governor's decision to hire an outside attorney -- prominent GOP attorney Butch Bowers -- to help lead the case.
"It's $360 an hour," said Stephens.
It's a taxpayer expense that Cooper calls a waste.
"Unfortunately, I think it just ends up costing more money," said Cooper. "We have a very professional staff of very experienced people."
Cooper was a vocal opponent of the legislation requiring photo ID at the polls, along with the move to cut the days of early voting and eliminate same-day registration.
In an August interview with Cooper, he called it, "One of the worst election pieces of legislation in the country."
"I'm not suggesting he's not a professional, and I don't have a problem with him having his own personal opinions," said Stephens. "The problem is when he goes on TV and starts expressing those opinions when there's pending litigation. That's the problem."
The Attorney General's office points out that the criticism came before the legislation became law.
As one of the highest-ranking Democrats in the state, Cooper is still considering a run for governor in 2016 to unseat McCrory.
Perhaps their first debate came two years early.