Pentagon delayed deployment of National Guard on January 6th

Second round of Senate hearings seek answers to the question why? - NBC's Susan McGinnis Reports

(NBC News) - Hearings into the security failures at the January 6 Capitol insurrection continued Wednesday.

The commanding general of the D.C. National Guard shifted the blame to top military leaders, telling lawmakers when Capitol Police urgently requested help, the Pentagon wouldn't authorize sending troops for more than three hours.

"I already had Guardsmen on buses at the armory ready to move to the Capitol," Major General William Walker testified.

He admitted that delay made a difference.

"That number could have made a difference. We could have extended the perimeter and pushed back the crowd," Walker said.

The dealay allowed rioters to infiltrate the building in a failed effort to sabotage the certification of Joe Biden's election victory.

Meanwhile, the acting Capitol Police chief is asking for big budget hike to beef up security, pointing to a 93 percent increase in threats to members so far this year.

"The possibility of a similar incident occurring in the current environment is a very clear and present danger," acting Capitol Police Chief Yogananda Pittman told lawmakers. 

It also comes amid new warnings of potential violence.  A senior law enforcement official tells NBC News a joint FBI-Homeland Security bulletin warns domestic extremist groups have "discussed plans to take control of the U.S. Capitol and remove Democratic lawmakers on or about March 4," a day some fringe conspiracy groups call America's "true inauguration day," and the day Donald Trump will retake the presidency.

The Homeland Security bulletin warning of potential violence says the extremists are still motivated by unfounded claims of election fraud.