The VP speculation will continue up to the moment Mitt Romney names his pick. We’ve identified three candidates — Virginia Gov. Bob McDonnell, Rep. Paul Ryan (R-Wis.) and Sen. Rob Portman (R-Ohio) — who appear to be the sort of candidates who would impress Romney. All three are solid conservatives with proven crossover appeal. All three are serious, disciplined candidates who could credibly step into the presidency if need be. They are not flashy, but sentiment seems to be shifting from the notion that Romney needs someone with panache and charisma to the belief that “safe” is a plus.

Jon Ward writes: “Most people expect the presidential race to remain tight, as a new New York Times/CBS News poll showed it to be on Thursday morning. If that trend continues this summer, it would increase the likelihood of a do-no-harm pick by Romney and reduce the chances that this already cautious candidate with a risk-averse campaign would go out on a limb.”

And yet the longing remains among Republican insiders, operatives and voters for a little more oomph. Certainly, the base has come around to Romney, but the desire remains for someone to inject some fun into the race. Yes, “fun” should not be underestimated.

That, I suspect, is why a figure like New Jersey Gov. Chris Christie (R) still has legions of Republicans rooting for his selection. The latest Christie YouTube highlights his appeal:

Okay, he is fun — and likable and effective with an everyman appeal. He’s not “safe” — he is far too spontaneous to script and steer away from controversy — and might well overshadow the top of the ticket.

But if the VP spot is not ideal for Christie because his personality is too big, his from-the-gut style of politics doesn’t mesh with Romney and he hasn’t been on the national stage that long, well, that still leaves a run for the top of the ticket in 2016 or 2020. Those who are similarly planning ahead should take note: They will face likely the most skilled and effective Republican in the country who will have proved himself in one of the toughest, bluest states.