By Mark Willen, Senior Political Editor June 18, 2008 Barack Obama isn't talking -- and he's ordered his staff to stay mum, too -- on all the speculation over his vice presidential running mate. That leaves the field wide open for the rest of us, so allow me to recommend moving one name up from dark horse to the short list -- former Sen. Sam Nunn of Obama began talking to Nunn three years ago, first seeking out his advice on nuclear proliferation, and later on all manner of defense issues, tapping into Nunn's expertise and experience. By all accounts, they hit it off and have become friends of a sort. And Nunn broke his no endorsement in the primary rule to come out for Obama in April. Nunn, who served four terms in the Senate, would add a lot to the ticket -- the foreign policy and defense experience Obama lacks, a history of fiscal conservatism, a measure of gravitas, a record of bipartisanship and an ability to connect with rural whites. Nunn's also known as a friend to business, with vote ratings from the Chamber of Commerce in the low 70s. Most important, he knows how Washington works, he's well respected by members of both parties in Congress and if Obama becomes president, he could be a major facilitator in winning support for the new administration's ideas. Nunn could also be an invaluable asset as nuclear proliferation threatens to become a top-tier issue in the campaign. He has won global respect for his work, in and out of the Senate, on efforts to prevent nuclear weapons materials and technology from spreading, especially to unstable states and terrorist groups. Given that McCain is using the issue as one way to distance himself from President Bush and that there is fresh evidence that nuclear weapon designs may have fallen into dangerous hands, Nunn could make Obama the stronger pick for nuclear security. Nunn might also help put Georgia's 15 electoral votes in play. He was always immensely popular, having won his third term in 1984 with 80% of the vote and running unopposed in 1990. Though it's been more than 11 years since he retired, he's still in close touch with his local roots. While the Peach State has voted Republican in the last three presidential elections, Obama already has it on his target list. He won the primary there on Super Tuesday, capturing a majority of whites as well as almost all African-American voters. He's already hard at work rallying and registering as many more Democrats as he can. There are some downsides. Nunn has the charisma of a wet noodle (though Obama hardly needs help in that category). Gay Democrats (and many Clintonites) will never forgive Nunn for his key role in blocking Clinton's 1993 effort to lift the ban on gays in the military. He's almost 70, doesn't exactly represent the face of change, and he sits on the boards of directors at Chevron, General Electric and Coca Cola (hardly a crime but hardly the image Obama is looking for). And while Nunn always won big in Georgia, when he tried to lend his support to other Democrats, he failed to be of much help. (Ask Buddy Darden). Still, we have to come back to what Nunn can offer if Obama is lucky enough to get elected, and that after all, is more important than what he can offer during the campaign. Obama is going to need people who understand the global landscape and know how to work Washington to get things done. And that's where Nunn can be a huge help.