The "veepstakes" speculation is in full swing:
Gov. Chris Christie of New Jersey is signaling that if called, he will serve.
Rep. Paul Ryan of Wisconsin has his fan club.
Ohio Sen. Rob Portman let slip to ABC News that he's being intensely vetted.
With Virginia in play, popular Virginia Gov. Bob McDonnell is being mentioned.
Ann Romney's seemingly offhand comment that a pro-life woman was under consideration to be Mitt Romney's running mate pulled in names like New Hampshire Sen. Kelly Ayotte, South Carolina Gov. Nikki Haley (who, as an Indian-American and a woman, counts as a two-fer in diversity points), and even former eBay CEO Meg Whitman, who lost the race for governor of California in 2010.
But if you ask me, the best choice for Romney's vice president is former Arkansas Gov. Mike Huckabee.
What does Romney want in a vice president?
The first rule in picking a vice presidential candidate is: Do no harm.
Romney ideally would pick someone whom voters will trust to be president if he (or she) must assume the office. (Although, for someone with Romney's relative youth and vigor, that's less important than it was for, say, John McCain.)
Romney needs someone who is an experienced campaigner, who won't make mistakes that hurt the campaign. The presidential campaign in the fall is not a good time or place to road test a candidate.
Running mates don't usually help you win an election, but they can help you lose one.
Romney needs to avoid McCain's mistake of picking a running mate who is more interesting and attracts more attention that he does.
Huckabee fits the bill perfectly. He not a guy to scare anyone, he's run the presidential gauntlet and been fully vetted, and while a pleasant and interesting man, he is a familiar enough figure on the national scene not to outshine Mitt Romney with novelty.
Several others on the shortlist also satisfy these minimal requirements.
But Huckabee would do something else for Romney -- something I don't think any other person can do: shore up the evangelical base of the party and ignite genuine enthusiasm for getting Romney/Huckabee to the White House.
It's not just Huckabee's style or political positions that would do this. It's the relationship of trust and love he's built with evangelicals and connections to evangelicals across the country. He is beloved. He can motivate.
And Romney needs this.
A poll released Tuesday by the Democratic firm Public Policy Polling shows President Obama pulling ahead in Virginia and North Carolina, two key Southern swing states: Obama has opened up a substantial 8-point lead (50 percent to 42 percent) in Virginia and is leading 47-46 in North Carolina.
Maggie Gallagher is a nationally syndicated columnist, a leading voice in the new marriage movement and co-author of The Case for Marriage: Why Married People Are Happier, Healthier, and Better Off Financially.