Conservative columnist George Will on Sunday suggested that President Barack Obama could be impeached after it was revealed that the Internal Revenue Service (IRS) targeted tea party groups.

The Associated Press learned last week that the IRS had apologized for what it was an "inappropriate" investigation into whether tea party groups were abusing their tax-exempt status.

"How stupid do they think we are?" Will asked during an ABC News panel on Sunday. "Just imagine... if the George W. Bush administration had IRS underlings, out in Cincinnati of course, saying we're going to target groups with the word ' 'progressive' in their title. We would have all hell breaking loose."

"This is the 40th anniversary of the Watergate summer," he added, reading a passage from former President Richard Nixon's articles of impeachment.

He has, acting personally and through his subordinates and agents, endeavoured to obtain from the Internal Revenue Service, in violation of the constitutional rights of citizens, confidential information contained in income tax returns for purposed not authorized by law, and to cause, in violation of the constitutional rights of citizens, income tax audits or other income tax investigations to be intitiated or conducted in a discriminatory manner.

"I think it would be irresponsible to start talking about impeachment over this," Democratic strategist Donna Brazile replied. "Clearly, there was some incompetence at some level or bureaucrats looking into all these applications in a rush after Citizens United [Supreme Court ruling] to see whether or not they were legitimate organizations with the word 'tea party' or 'patriot' in it. Yeah, there are progressive patriots as well."

"Given what George has just said, you better get ready for your audit," ABC News White House correspondent Jonathan Karl quipped to Will.

"The IRS commissioner was a Republican appointed by [former President George W.] Bush, who his term expired in November," Brazile pointed out.

There is no evidence that President Obama directed or even knew of the targeting of tea party groups.

Watch this video from the ABC's This Week, broadcast May 12, 2013.