Who should be Obama’s running mate?

With his party’s nomination in hand, would Barack Obama be better off with Hillary Clinton as his running mate?

Obviously she thinks so. If she’s not on the ticket and Obama wins, she’ll be sidelined for at least four and perhaps eight years, at which point she’ll be 68. Every year means more rising stars to compete against her. Some powerful Democrats also want her on the ticket. They argue that Hillary guarantees a unified and galvanized party working together toward a November triumph.

Maybe. But for every reason Obama has for considering Hillary Clinton, there are at least twice as many reasons to flee from the idea.

Start with the most obvious. Next to President Bush, Hillary Clinton is probably the most unpopular political figure in the country. How does such a polarizing figure help you make a pitch to the electorate for “unity”? How do the politics of the ’90s make the case for “change”?

Second, while Hillary unites the Democrats, Obama ideally wants someone who appeals across the aisle to Independents and soft Republicans. The 8th Congressional District here on the Eastside of Lake Washington is a perfect test case. It usually supports Democrats for president, but prefers Republicans for Congress. Would Hillary on the ticket be a drawback or an asset to winning the 8th in November?

Third is the issue of trust. Would Hillary be subservient to Obama’s agenda or her own? And keep in mind that when Hillary hops aboard you get a two-fer: all of her baggage and all of BILL’S baggage. Does Obama really need all of that?

But if he doesn’t pick Hillary, who should he select? Here are six strong possibilities.

SAM NUNN. A southern Scoop Jackson, Nunn spent a quarter century in the U.S. Senate from Georgia, developing bipartisan praise for his grasp of national defense issues and international relations. His one drawback is that he’s been out of the game for a decade. Party liberals would also flinch at his moderate to conservative (for a Democrat) tendencies. He voted against the Clinton tax hikes and opposed uncloseted gays in the armed forces.

It’s more likely that Obama will choose someone from outside Washington, D.C., probably one of the following four governors.

TIM KAINE. The first-term governor of Virgina, Kaine is 50, Catholic, and popular in an important battleground state in November.

TED STRICKLAND. The 2004 election got down to just one state, Ohio. In the last four years, voters in that swing state veered sharply toward the Democrats after growing weary of Republican misrule and malfeasance. Ted Strickland, a youthful-looking 67, was elected governor in 2006 after a career as a minister and congressman.

ED RENDELL. The 64-year-old two-term governor of Pennsylvania, Rendell is a onetime district attorney and former mayor of Philadelphia. He is also a former chairman of the Democratic Party.

KATHLEEN SEBELIUS. The daughter of a former governor, Sebelius, 60, has been in politics most of her adult life. She has also been a strong supporter of Barack Obama. One drawback: Kansas is not as important as Pennsylvania, Virginia and Ohio.

Then there’s the fantasy choice that would effectively end the race: COLIN POWELL. But the former secretary of state and national security adviser is an old friend of John McCain’s and probably won’t do anything to oppose him.

Any one of these people would be a vast improvement over Hillary Clinton, who would likely prove true one of Richard Nixon’s political maxims: “Vice presidents can’t win you votes, they can only lose you votes.” Nixon should know. He was on five national tickets.