Former Republican National Committee (RNC) chairman Michael Steele tells Breitbart News that Chris Christie’s endorsement of Donald Trump Friday was a pivotal moment in the campaign.

“One word, BOOM! Exclamation point,” Steele said in an interview. “Today after what we saw Marco Rubio do last night, he was out there attacking Trump on twitter and Trump was like, got one for you, BOOM!”

“Now the guy who defined Marco a few weeks ago is back in the game. He’s engaged, and he’s working with Trump. BOOM!”

Christie formally endorsed Trump in Texas at a press conference Friday before a major rally, calling Trump a longtime personal friend and saying that Trump is the most feared Republican to square off against Democrats in the general election. Christie previously scored a massive triumph when he mocked Marco Rubio’s memorized scripted talking points in a Republican debate in New Hampshire.

“The man is amazing,” Steele said of Trump. “I’ve never seen anything like this in politics. I don’t think there’s any descriptor for what Donald Trump has done to the political process and the Republican Party. There’s no one else playing this game better than him.”

Steele noted the size of the crowd at the Trump rally in Fort Worth.

“10,000 people in this stadium, those are general election numbers,” Steele said. “If there’s 10,000 in the primary what do you think the general is going to be?”

Former House Speaker Newt Gingrich also declared Friday that Christie’s endorsement of Donald Trump is a great sign for Trump’s chances to become the standard-bearer of the Republican Party.