This isn't the first time Jeb's piped up with this, of course. He made the same claim in the first debate, and his campaign ran with it, even pairing it with an image of George Bush standing on the rubble of the collapsed World Trade Center. It's a talking point. As long as you don't count the THOUSANDS OF DEAD PEOPLE ON 9/11, the Bush administration did a fabulous job.
If nothing else, it shows us where a Jeb Bush administration would set the competency bar. Everyone gets one free 9/11 before we're allowed to start keeping score, right? And, what the hell, one astonishingly bungled Katrina response, and one massive near-collapse of the entire global economy. If you spot him all of those, by gum, a Jeb Bush administration can't help but be a rousing success* (*exceptfor911).