From The Hill:

"I think John McCain's reaction to what happened in Russia did not reflect well on the position he should have taken, and that is one of understanding we have one president in this country, and that Secretary of State Rice and President Bush need the support of both presidential candidates in a very tricky time as it relates to Russia and the neighboring states that are trying to establish democracies," McCaskill said of the Arizona senator's reaction to the conflict between Russia and Georgia over South Ossetia.

It's fine for Obama supporters to make this kind of criticism, but it also underscores the need for Obama to get a foreign-policy VP. Coming McCaskill, voters might shrug this off; coming from someone like Biden, it could carry a lot of weight.