A Fox News Sunday segment with Karl Rove and former Ohio Governor Ted Strickland (D) quickly turned from a debate about Gov. Chris Christie (R-NJ) to an attack on Strickland’s political past.

Christie Denies Knowing About Bridge Scandal in Radio Interview

The two were discussing whether Christie had any knowledge that his top aide caused a traffic jam out of alleged political retribution, when Rove said, “Let’s go back to 2008 and Joe the Plumber. Governor Strickland’s own appointee, as head of the employment commission, was found to have been accessing confidential government databases in order to find out confidential information, private information, about Joe the Plumber and leaking it to the press.”

Joe the Plumber is the nickname that was given to Samuel Wurzelbacher during the 2008 presidential campaign. He was spotlighted for asking then-candidate Obama a question about tax policy.

Bad Blood With Chris Christie? Rick Perry Responds

Rove threw Strickland’s attack on Christie as being "incompetent or lying" back at him. “Be careful to throw stones,” he said.

Strickland maintained that no confidential information about Joe the Plumber was leaked to the press, but Rove responded, “I’d go back and look at the public records if I were you.”

Watch the back-and-forth in the clip above.

How Much Attention Should the Media Give the "Hillary Papers"?