Don’t be Rudy Giuliani. You probably think you wouldn’t have Rudy’s problems in a Republican primary. Yes, you’re both combative Northeasterners from the party’s moderate flank, but unlike the former mayor you aren’t a social liberal with a public history of adultery (and a few drag performances thrown in).

But what felled Giuliani in 2008 wasn’t just “values” issues. It was the former mayor’s apparent belief that being a national hero was a sufficient qualification to be president — that he could just show up, be “Rudy,” and the rest would take care of itself.

As another charismatic politician defined by your handling of a catastrophe, you’re vulnerable to the same temptation: the belief that you, personally, are the solution to the Republican Party’s many problems, and that you can just run on your own awesomeness without specifying where you would take the country if you won. That act wears thin in a long campaign, and it’s likely to wear especially thin in a party that needs a new agenda as badly as Republicans do today.