I emphasize, again, that these rankings do not reflect my personal preferences, but rather my educated guesses as to which prospects seem most likely to win the nomination. I also stress that such guesses are no more scientific than handicapping horse races. Those who know the president's thinking on this don't talk, and those who talk don't know.

Moving Elena Kagan from first to second, for example, is no reflection on her other than the fact that for all her assets, she has not been a judge and therefore has not had the same opportunity as Diane Wood to compile an outstanding record on the bench.

I've also dropped Leah Ward Sears from fourth to seventh. While I still have reason to think that she is an outstanding candidate, we haven't heard much about her from the mentioners who are closest to the real insiders. One reason may be that the political payoff for Obama may be greater if he picks a Hispanic-American than if he picks an African-American.

Here are the new rankings:

1. Diane Wood
2. Elena Kagan
3. Janet Napolitano
4. Jennifer Granholm
5. Sonia Sotomayor
6. Vanessa Ruiz
7. Leah Ward Sears
8. Valerie Jarrett
9. Pam Karlan
10. Merrick Garland

This ranking is based on media reports, online chatter and surveying various experts. It reflects the assumptions that President Obama will almost certainly want to choose a woman; would like to choose a Hispanic, but only if no other candidate does markedly better than the best available Hispanic on the criteria that follow; wants someone liberal enough to be a political hit with Democrats and moderates but politically difficult for Republicans to oppose; wants a stellar intellect with great judgment and the ability to write rhetorically powerful and logically rigorous opinions, so as to go toe-to-toe with brainy conservatives such as Justice Scalia and Chief Justice Roberts; wants a nominee with whom he has personal rapport; and wants a nominee with views roughly similar to his own personal convictions.

Finding someone known to have the ideal mix of views will be difficult, perhaps impossible. Most of the prospects have not specified their views on all or even some of the biggest issues that will confront the court. And as a general rule, lawyers and judges who lean left on issues like abortion and campaign finance reform also tend to lean against the executive branch in cases involving presidential war powers -- which happen to be the cases most likely to affect the success or failure of Obama's presidency.

With those caveats, here are the top 10:

1. Elena Kagan
2. Janet Napolitano
3. Diane Wood
4. Leah Ward Sears
5. Sonia Sotomayor
6. Jennifer Granholm
7. Vanessa Ruiz
8. Valerie Jarrett
9. Pam Karlan
10. Merrick Garland

News reports have named all but Sears, Ruiz, Jarrett and Karlan as on the list now being vetted by the administration.