Jeb bush's new video starts with this question - "What makes us who we are?"
It is a question that Bush has been struggling to answer since he launched his campaign for president. Recent polls suggest that Bush is largely an after thought, if that, for many Republican voters.
Still, Bush clings to the notion that when all is said and done, Republicans will reject Donald Trump, Ted Cruz, Marco Rubio, Ben Carson and all the rest of the GOP field in favor of someone who last held public office 9 years ago.
If Bush is right, it would be one of the biggest comeback stories in modern politics.
While this ad suggests that Bush is the only one who can take on ISIS, Bush has a more pressing concern at tonight's debate in Las Vegas - proving he can take on Trump and the rest of the field.