With the Clinton campaign now saying they will stay in the race even if they lose delegates in Texas, it's worth putting into perspective just how difficult it would be for them to close Barack Obama's lead in pledged delegates. For Clinton to pull ahead, she will need to win 57% of the remaining pledged delegates. To keep that number from rising even higher, they of course need to win 57% of the delegates on Tuesday, which would mean getting at least 213 delegates to Obama's 161 -- a 52 delegate advantage. If they net anything below 52 delegates, they fall even further behind. This is the key number to keep in mind when watching the election returns.
And, of course, even netting 52 delegates is hardly a big win. The Clinton campaign picked Texas and Ohio as its battleground because those states are particularly Clinton-friendly. The remaining primary states include several -- like Mississippi, Oregon, and North Carolina -- where Obama is likely to rack up major wins. That means that Clinton needs to gain well over 57% of the delegates in the states that are better for her. The only way she could possibly do this would be to utterly destroy Obama's reputation, make him a radioactive figure, like Al Sharpton. This also seems like an extreme longshot, though the Clinton campaign appears to be attempting to pull it off with its flurry of attacks.
Now, in Clinton's favor, she doesn't necessarily need to win pledged delegates. I think if she comes close, and has the momentum, she could possibly win it with superdelegates without too much blood on the convention floor. But Clinton needs to dramatically reduce Obama's lead in pledged delegates. If she only wins narrowly Tuesday, even the goal of getting close in pledged delegates will become more remote, and her continuing candidacy will be impossibe to justify for anybody who has the Democratic Party's interests at heart.
--Jonathan Chait