Charles Krauthammer said Wednesday on "Special Report with Bret Baier"  that, despite Jeb Bush's attacks on Republican presidential front-runner Donald Trump at Tuesday's GOP debate in Las Vegas, it won't do anything to help his campaign.

"I think that ship has sailed," the syndicated columnist and Fox News contributor said. "I'm happy to see Jeb stand up and get tough. I think he's had a really tough campaign. I don't think it's going to move the needle one iota."

Bush went after the billionaire businessman last night, calling Trump a "chaos candidate" who "will be a chaos president."

"The problem is this: had [Jeb] done that in the first debate, or the second, at a time when Trump was rising...I think it might have had an effect."