Lawmakers clash during IRS hearing: Rep. Issa turns Rep. Cummings' microphone off

Tempers flare on Capitol Hill.

During a House Oversight  hearing about whether the IRS intentionally targeted conservative groups seeking tax exempt status, former IRS official Lois Lerner pleaded the fifth yet again.

Issa: GOP-led IRS targeting probe may be at 'dead end'

The hearing turn ugly when the chairman of the committee, Republican Darrell Issa, tried to shut it down altogether, saying "Seeking the truth is the obligation of this committee, and I can see no point in going further."

[youtube http://www.youtube.com/watch?v=N8ApWl6xd5k?rel=0&w=560&h=315%5D

That set off ranking Democrat Elijah Cummings.

As he stood up to leave, Cummings spoke into his mic: "Mr. Chairman? Mr. Chairman, I have a statement."

Issa ignored him and started to leave while Cummings continued. "Mr. Chairman, you cannot run a committee like this," says Cummings. "You just cannot do this.We're better than that as a country, we're better than that as a committee. I have asked for a few minutes..."

Issa muted Cummings' mic as he spoke. Issa returned to his seat and turned the mic back on, telling the rest of the chamber they were free to leave. “We've all adjourned, but the gentleman may ask his question,” Issa said.

OutFront: Bill Kristol and CNN contributor Paul Begala.