Jonah Goldberg‘s latest column at National Review Online explains why potential Republican presidential candidates need to prepare well for the 2016 campaign.

This is my biggest gripe about some of the GOP candidates in recent years. They don’t think they have to do their homework, perhaps because they aren’t so much running for president as running for greater celebrity.

Consider Herman Cain. I love listening to him, and so do a lot of conservatives. He’s smart enough to be president. But he simply didn’t do his homework, and he acted like that was something to be proud of, as when he bragged about not knowing the names of leaders of “small, insignificant states” like Uzbekistan (which he jokingly pronounced “Ubeki-beki-beki-beki-stan-stan”).

The one thing you cannot buy in politics is charisma. If you could, Mitt Romney would have bought a pallet of it at Costco and he’d probably be president now. Cain and Perry had the charisma, the natural political talent, and they squandered it by thinking all they needed was the sizzle without the steak.

I have similar worries about Ben Carson, who’s on a book tour that feels a lot like a walk-through for a presidential run. Carson is amazingly popular on the Republican circuit. He is to older traditional conservatives what Rand Paul is to younger libertarians.

A world-renowned neurosurgeon, devout Christian, and an African-American with a rags-to-riches story that beats any and all possible competition, Carson has enormous strengths. (Contrary to a lot of nonsense you hear daily on MSNBC, most of the base of the GOP would love to nominate a conservative black guy.) But while he speaks eloquently and passionately about the importance of doing homework in his own life and for children everywhere, it’s not obvious he’s taken those lessons to heart when it comes to politics. …

… You can skate by with a lot of platitudes about common sense and the evils of political correctness (all of which I agree with) when speaking to an audience of your biggest fans. Perry learned that the hard way when he encountered audiences that didn’t care that much about the Lone Star State.

Politics, particularly presidential politics, has to be about persuading people who disagree with you, not just telling those you had at “hello” what they came to hear.