It seems clear to me that Senator Obama needs a complementary VP candidate who can attack McCain's biggest strength (and IMHO Obama's biggest weakness) namely his national security expertise. Since the Democrats have conceded this policy area some years ago (really since Scoop Jackson and Sam Nunn) to the Republicans, it's rather hard to find someone with respectable enough record.

Richardson, Biden and James Webb probably are the three quick candidates (left, middle and right of the party). The problem is all have some weaknesses of their own and would probably violate the rule #1 of vice presidential candidates, namely do no harm to the top of the ticket (Eagleton, Ferraro, Quayle, etc). The regional balancing of the VP ticket probably isn't that important to the Democrats this year (and Gore proved that it didn't matter too much from the Dem perspective) given the vast superiority in turn out rates in key swing states. If I had to hazard a guess, it'd be Tom Daschle

Neil Richardson, Atherton, CA

How about Obama & Colin Powell, that would bring the Dems ticket far enough to the right to stave off McCain.

Glenn, worcester, us

Clinton/Obama is possible and a strong ticket. Obama has good debating skills and would be a power as Speaker of the Senate - and be a good stepping stone to take on the role of President in 8 years. However, I can not see Clinton accepting a role as VP and if asked it would undermine Obama's claim to be a new voice in Washington.

Clinton/Obama is a STRONG choice for the future, but Clinton has to win for that to even be an option.

Chip Clark - American in UK, Edinburgh, Scotland

Whether Clinton or Obama becomes the Dem nominee, they will not choose the other - it would create a constant power and attention struggle, and would quickly create a divided house that would mean losing the legislative branch at the mid-term election. My bet is John Edwards for Obama, which creates a rhetorical juggernaut but runs a risk of going too far left, and Richardson for Clinton, who helps with the Hispanic vote but is a verbal loose cannon.

McCain will probably go Southern, probably conservative but could go moderate to help cement cross-party and independent appeal. Someone dynamic. Could be Crist, Sanford, Thompson (not Huckabee) or even Condoleeza Rice. As an extreme dark horse, try Bobby Jindal, the Indian congressman and current governor of Louisiana - if not this cycle, expect to hear his name next time around.

The bigger questions, however, are if:
1. The Dems go to a brokered and/or botched convention
2. Both nominees accept public funding

H, Dallas, Texas

An Obama/Clinton or Clinton/Obama lineup would ensure parallel presidencies, continually vying for prominence - double the trouble!

Robbie Rohan, Great Chart, UK

Bill Richardson made no enemies on the campaign trail when he ran against Senator Clinton, Senator Obama, et al, for the nomination. He is the popular two-term governor of a crucial swing state, New Mexico, in an increasingly important part of the country (the south-west) due to its high levels of population growth. He is also a Hispanic--popular in his state with his fellow Hispanics--with cross-over appeal to both whites and Native Americans, and he is is a former seven-term member of the U.S. Congress, U.S. Ambassador to the United Nations, and U.S. Energy Secretary (the only Energy Secretary who has compiled a renewable resources profile). He is personable (which would help balance Mrs. Clinton's often frosty demeanor) and experienced (which would greatly help Mr. Obama). He'd make a great Vice Presidential running mate or future Secretary of State.

Chris Hassel, Saint Paul, USA / Minnesota

The way for Obama to beat McCain is not to try and be more liberal then him, but try and apeal to his right and give him trouble with his core coservative vote. As such VPs like Sebelius and Clinton are not applicable. Obama should appeal accross the divide and go for an independent businessman like Bloomberg, or war leader like Wesley Clark.

George, London, UK

A Democrat ticket pairing Clinton and Obama (in either roles) would mean a sure Republican victory. There is no more certain way to lose an election than to disenfranchise the US's white males.

Paul Doering, Rochester, USA/New York

Clinton will go on to win the nomination after winning the primaries in Ohio and Texas. But Obama will be so strong, that she'll have to give him the VP slot now, even if she doesn't want to. He'll take it, and he'll become the absolute lundisputedeader of the party within 4-8 years. If he takes the VP slot, he WILL be President... it'll be just a matter of WHEN. McCain' choice is influenced by who is nominated by the Democrats. If Clinton wins, McCain's choice is Huckabee or Crist. Crist will upset conservatives... but wins Florida. But if Obama prevails, don't be surprised if McCain picks former NY Governor George Pataki. It'll anger the conservatives again, but Pataki will help take NY if there's no Hillary, as there are a LOT of people upstate and in Western NY (and in the city for that matter) who will quietly reject a black. If McCain takes NY, he wins. Mark my words. If it's Obama, McCain picks Pataki.

James, Las Vegas, Nevada