Joe Scarborough: Newtown Shooting Made 'Ideologies Of My Past' On Guns Irrelevant (VIDEO)

Visit NBCNews.com for breaking news , world news , and news about the economy

Joe Scarborough said on Monday that the massacre in Newtown had forced him to rethink his "long-held" belief about gun rights.

In a lengthy monologue, Scarborough talked about how shaken up he had been by the killing of 20 children at Sandy Hook Elementary School on Friday. He noted that his children's ages averaged that of some of the murdered victims.

"From this day forward, nothing can ever be the same again," he said. "... Let this be our true landmark ... politicians can no longer be allowed to defend the status quo."

He said that he was a "conservative Republican" who had been solidly aligned with the NRA during his time in Congress, and had previously held libertarian views on the Second Amendment. But he added that Friday "changed everything":

"I knew that day that the ideologies of my past career were no longer relevant to the future that I want, that I demand for my children. Friday changed everything. It must change everything. We all must begin anew and demand that Washington's old way of doing business is no longer acceptable. Entertainment moguls don't have an absolute right to glorify murder while spreading mayhem in young minds across America. And our Bill of Rights does not guarantee gun manufacturers the absolute right to sell military-style, high-caliber, semi-automatic combat assault rifles with high-capacity magazines to whoever the hell they want.

It is time for Congress to put children before deadly dogmas. It's time for politicians to start focusing more on protecting our schoolyards than putting together their next fundraiser. It's time for Washington to stop trying to win endless wars overseas when we're losing the war at home ... For the sake of my four children and yours, I choose life and I choose change."