Breaking from its practice of laying low following shootings, the National Rifle Association Thursday aggressively pushed back against anti-gun groups backed by billionaire Michael Bloomberg and their "#WhateverItTakes" campaign to promote gun control.

The NRA's Institute for Legislative Action, headed by Executive Director Chris Cox, Twitter bombed Bloomberg's Twitter hashtag and associated Capitol Hill rally featuring the father of a Virginia TV reporter shot dead on live TV.

"Criminals will do #WhateverItTakes to be criminals. More laws won't help," said one NRA tweet. "What does #WhateverItTakes mean to anti-gunners? Repealing the #2A? Confiscating all firearms? Creating a defenseless citizenry?" said another. And in a third, the NRA promised: "We'll do #WhateverItTakes to protect the #2A!"

Thursday was "Whatever It Takes" day around the country, sponsored by the Bloomberg-backed Moms Demand Action and Everytown for Gun Safety.

At the Capitol rally, Andy Parker, father of slain reporter Alison Parker, demanded laws promoting more extensive background checks and threatened to run politicians who disagree out of office. He has previously assailed the gun lobby.

"I know that weakening the stranglehold of the gun lobby won't happen overnight. I know, too, that passing background check laws won't prevent all acts of gun violence from taking place. But we must keep the pressure on our lawmakers until they do the right thing. And if they won't, find their replacement," said Parker, joined by both of Virginia's Democratic senators and Gov. Terry McAuliffe.

Alison Parker's killer passed both a state and federal background check.

The NRA said that no laws proposed by gun control advocates would have caught the mentally disturbed killer, and that instead lawmakers should focus on increasing mental healthcare in the nation.

The NRA-ILA recently indicated that it was taking a more aggressive approach against Bloomberg when they it began running TV ads against him. Thursday's Twitter bomb was the latest in their effort to challenge the claims by Bloomberg-backed groups.

Cox has also stepped up his efforts, writing in several newspapers this week that Parker's killer would not have been stopped by any of the gun control legislation recently proposed.

"The fact is no piece of legislation pushed by gun control advocates would have stopped him from committing this brutal crime," wrote Cox. "But to them, that's beside the point. They will use any tragedy as an excuse to push their agenda regardless of the facts involved. They're not interested in solving problems. This is politics, pure and simple. What's most egregious about it is by exploiting tragedy to push gun control, they deflected the conversation away from real solutions that would solve our nation's pressing problems — like fixing our broken mental health system."

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com.