A detailed estimation of the Texas delegate split. Note that Texas is partly a primary (but at the district-level!) and partly a caucus. Great work, Election Inspection!
Bottom line: the caucus portion could put Senator Obama over the top, even in Texas! EI says Obama 98, Clinton 95 delegates. Now let's wait for March 4... Even if Senator Clinton wins both Texas and Ohio, as long as the margins are 10% or less, Senator Obama should come out even or ahead on March 5.
Unfortunately for Senator Obama, that might not be enough. He has to win at least one major state (Texas, Ohio or Pennsylvania) and get a margin large enough that Florida/Michigan will not matter. This site appears to say Senator Clinton will get 111 more delegates than Senator Obama from Florida/Michigan (no idea of the assumptions - maybe all "uncommitted" to Obama?) That means Senator Obama will have to get a lead of ~125 pledged delegates excluding Florida/Michigan. Otherwise, the race will get ugly. A tough proposition, to say the least.
But - maybe efforts like this could propel Senator Obama to the nomination (from an NYT article):
“You are going to see Senator Obama campaign [in Texas] the way he did in Iowa,” Mr. Figueroa [Obama’s national field director] said. “We’re going to take him to little communities so that he’s not only going to touch voters with his words, he’s going to be able to reach out and physically touch them.”