FAIRFAX During the past several days, Washington and Richmond have been buzzing about whether Gov. Tim Kaine should be the Democratic Party's vice presidential candidate. This public airing of Kaine's qualifications is just what Barack Obama wants, so that any problems with a potential running mate can emerge before the die is cast.

Make no mistake about it: Neither Kaine nor any other potential vice presidential nominee is a perfect choice. No one person is excellent in all respects. The only perfect choice a presidential nominee can make is a perfectly bad one -- such as Dan Quayle, whose deer-in-the-headlights introduction to national politics in 1988 made it harder for Republican presidential nominee George H.W. Bush to win that year.

Above all, an Obama-Kaine ticket would clearly resonate in terms of Obama's campaign mantra, the need for change in the way Washington does business. As a moderate governor of a Southern state, Kaine is far from the gridlocked politics of Washington that generates such anger among voters (though the governor does contend with the gridlocked politics of Richmond, which resembles Washington more every day).

Kaine's key strength is that he would complement Obama on the change file. He is intelligent, articulate, a natural campaigner, and a highly effective debater. As Kaine was one of Obama's first major endorsers and a top campaigner for the Illinois senator, the two men have already learned to work with -- and trust -- each other. The ticket would be not unlike the Bill Clinton-Al Gore ticket of 1992, which joined two politicians of similar backgrounds to try to turn the page on an earlier President Bush.

In a way, Obama probably has to choose Kaine or someone with a similar change-oriented political profile. For Obama to settle on an old Washington hand as a running mate would destroy the central message of a campaign that has generated so much enthusiasm, particularly among young voters.

The other side of this change coin, however, is experience. While governors have much more practical experience than senators, and arguably make better presidents than someone who has never run anything larger than a Senate office, Virginia's first-term governor does not help Obama where the Republicans are most inclined to attack: foreign and military policy. While the Obama team may think that July's road trip could inoculate the ticket against such criticism, there are a lot of things that can go wrong in the Middle East between now and November. If conditions there do deteriorate, John McCain's experience and toughness may seem more appealing to crucial swing voters than a ticket where both candidates are relative newcomers with very slim foreign policy credentials.

But alternatives to Kaine who are more seasoned foreign policy hands have their own liabilities. Sen. Joe Biden (D-Del.), one of Obama's former 2008 nomination campaign rivals, could add decades of foreign policy experience. But Biden is long-winded and gaffe-prone, which makes him a risky choice, one likely to drain the excitement out of the campaign. Other foreign policy experts field-tested during the 2008 nomination campaign include Sen. Chris Dodd (D-Conn.) and New Mexico Gov. Bill Richardson, but neither appears to be on the current short list.

The best Democratic vice presidential choice for those who want to address McCain's toughness head-on is probably Sen. Jim Webb (D-Va.), but he has ruled himself out as a running mate.

Kaine could also help secure an Electoral College majority for the Democrats. Before Kaine emerged as a favorite for the vice presidential nomination, Virginians said they were nearly evenly divided on this year's presidential candidates. A Virginian on the ticket may put Virginia's 13 electoral votes in the hands of Democrats for the first time since 1964. Kaine might also be of use in North Carolina, another Southern state being targeted by the Obama team.

Although he is not yet nationally known, Kaine could also help in other parts of the country if he were a vice presidential nominee. The governor's fluent Spanish and his work as a missionary in Honduras as a young man can help the campaign reach Latino voters in highly competitive states like Colorado, Nevada, and New Mexico. And then there's Florida, where younger Cuban-American voters say they are less interested in the GOP than their Castro-hating parents were. (For Democrats, there is always Florida . . . ).

Other potential running mates could also help in terms of geography, but also raise questions. Former Sen. John Edwards of North Carolina, who finished third in the 2008 presidential nomination contest, could add an economic populist dimension to the ticket. But he did not carry North Carolina for Sen. John Kerry (D-Mass.) as Kerry's running mate four years ago -- and Edwards' own 2008 campaign fizzled. Sens. Bill Nelson (D-Fla.) and Claire McCaskill (D-Mo.) could be interesting choices for geographical reasons, but so far neither has emerged as a particularly high-profile lawmaker.

Although a former Clinton loyalist, Pennsylvania Gov. Ed Rendell might be most able to guarantee the Democrats cross the finish line in first place. His selection as a running mate would nail down his home state (which the Democrats won in 2000 and 2004), and probably also secure the neighboring industrial state of Ohio, a state John Kerry almost won four years ago. Rendell's gritty working-class persona, extensive political experience and sharp political mind would make him a safe choice on the campaign trail. But he possesses limited Electoral College upside potential if the Obama campaign believes it is already winning Ohio and the rest of the industrial Midwest. Rendell is also far less of a voice for change than Kaine would be.

A Kaine selection, in other words, means the Obama campaign is trying to win a far larger victory than the narrow Electoral College majorities George W. Bush secured in 2000 and 2004. With Kaine, the Democrats would be swinging for the fences, trying to recreate the kind of drubbing the Republicans endured in 1964 when the GOP nominated Barry Goldwater of Arizona and the Democrats last carried the Old Dominion.
Stephen Farnsworth teaches courses in political communication and journalism at George Mason University, where he is an assistant professor of communication. He is the co-author, with S. Robert Lichter, of "The Nightly News Nightmare: Television's Coverage of U.S. Presidential Elections, 1988-2004."