Clinton would likely win Puerto Rico and Pennsylvania so she just needs to win a couple between now and then to assure herself of a lead that either earns her the top of the ticket if a deal is made or it goes to a brokered convention (which no one wants)
Obama's chance is to sweep everything and build momentum to the point where he wins Texas in March. Then he has a chance.
Voters seem to immune to momentum this campaign season. I don't think much will change between now and March. Lots of voters want Obama and lots of voters want Hillary. It seems that they don't care about what the last state did.
