Kyle E. Moore/Comments from Left Field
At this point, Hillary Clinton's arguments have all been shot down. Florida and Michigan will no longer save her, she has no hope of winning the pledged delegate lead, and she has no hope of winning the popular vote. By contrast, Obama has proven that even when his campaign is getting kicked around and beaten with baseball bats, he can still perform, and he can still come up with a meaningful as opposed to a symbolic win.
There is a way for her to remain in the race, and not do herself, her party, and the eventual nominee harm, and that would be to go 100% against McCain. Stay in the race, ignore Obama, and let's have instead of a two on one gang up on Obama, a two on one gang up on McCain. Under these conditions, I would be more than happy for Mrs. Clinton to remain in the race, it would give the voters in the remaining states a sense that they are contributing, and hopefully create more excitement for the eventual nominee, and it would double the intensity of attacks on McCain, and hopefully, for the first time since McCain looked to be a doomed candidate late last year, actually force the media to put him in the hotseat.
But barring that, the race is over.