WASHINGTON -- Rep. Darrell Issa (R-Calif.), chairman of the House Oversight and Government Reform Committee, seemed to catch everyone off guard Wednesday when he suddenly pulled the plug on his committee hearing before witnesses could even testify.

Issa read his opening statement for the hearing on potential abuses of taxpayer funds by the White House's new political office, and let his Democratic counterpart, Rep. Elijah Cummings (D-Md.), read his statement before declaring the hearing over. Two witnesses who came prepared to testify were dismissed. A source who was in the hearing said one of Issa's witnesses, Carolyn Lerner, the director of the independent Office of Special Counsel, appeared to leave angrily.

"She didn't say a single thing," said this source, who requested anonymity. "She literally just left the hearing room."

So what happened?

A Cummings aide said he had no warning the hearing would be cut off before anyone could testify, and said there was no reason for doing so.

A request for comment from Issa's office was not returned.

But two things were apparent to those following the hearing: First, Issa began the hearing irritated that the White House had dismissed his subpoena to compel Obama's political office director, David Simas, to testify. He called it "deeply disturbing" that White House counsel Neil Eggleston said Simas was immune from a congressional subpoena. Second, and perhaps more tellingly, Issa may have wanted to prevent Lerner from testifying since, based on the written testimony she provided ahead of the hearing, she was planning to say the White House Office of Political Strategy and Outreach had done nothing inappropriate, which contradicted Issa's claims leading up to the hearing.

Lerner's shop is charged with enforcing the federal Hatch Act's prohibitions against federal employees engaging in political activity, which makes her the go-to person in the event of allegations of wrongdoing by the White House political office. She was prepared to tell the committee she did her homework and found nothing wrong.

Per her prepared remarks:

OSC received copies of correspondence between Chairman Issa and the White House concerning the establishment of the Office of Political Strategy and Outreach (OPSO). The White House did not consult with OSC about establishing the OPSO. However, based on our review of the White House correspondence to the Committee, it appears that the White House adhered to OSC guidance in determining the scope of activity for the office. To the extent that OPSO’s activities are limited to those described in the White House correspondence, OPSO appears to be operating in a manner that is consistent with Hatch Act restrictions.

It's unclear whether Issa will reschedule the hearing and allow the witnesses -- the other was Scott Coffina, a former associate counsel to President George W. Bush -- to testify. It's also unclear whether Issa is prepared to go to court over his subpoena being defied.

The White House, meanwhile, took shots at Issa for needlessly issuing subpoenas. As of Wednesday, Issa has issued a total of 99 subpoenas since becoming committee chairman -- more than the past three chairmen combined.