Ron Paul is running a moneyball strategy. He's trying to get the most delegates for the least amount of money. He's also making sure to go after delegates that are legal floaters -- they can support anyone regardless of how their state voted. If this strategy pays off, then Ron Paul can continue to get clobbered among the unknowing sheep in places like Michigan and South Carolina, but still rack up all the delegates who are making up their mind independently.
The problem is that even on this strategy, he doesn't have a chance of winning. The latest results in Mississippi, Alabama, American Samoa, and Hawaii don't change this fact.
There are 2,286 delegates up for grabs in the whole shebang, meaning that 1,144 delegates are needed to get a majority. Romney for example has 391 legally bound delegates, but projections among the other delegates have him controlling about 454 delegates.
The total number of delegates left in the entire race is 1289, meaning that if Ron Paul won EVERYTHING from now until the convention, he would barely have enough votes to win. Needless to say, that scenario is unlikely. Ron Paul has done terribly with bound delegates, probably becuase he insists on avoiding, big, winner-take-all states that he is sure to lose.
Consider how unlikely Ron Paul is to win. Pretend his moneyball strategy continues to work and he picks up EVERY legally unbound delegate. That would move him to about 197 total delegates. Now we have to look at how he's doing at getting bound delegates. Currently he wins about 3 out of every 100 bound delegates, meaning that winning at his current rate, he would get about 34 more delegates (1139 bound delegates up for grabs times a 3% rate of winning them). He wouldn't even get to 250 delegates.
Now I understand the criticism that the media, by reporting these number is partially to blame for discouraging people from voting for Ron Paul when they originally wanted to. But at this point, there's nothing about the media that is driving Ron Paul's loss anymore. Now there are just too many Romney and Santorum supporters that WILL NOT vote for Ron Paul, making his defeat inevitable.
Will Ron Paul shift the convention more to the right? Maybe, but that's actually a risky strategy because rightward does not necessarily mean "more like Ron Paul." Would the Ron Paul nation be angry if they sent libertarian delegates to a brokered convention and that tipped things toward Santorum or Gingrich? I would think so. It's good to stand up for what you believe in *hat tip to RP*, but the situation is really uncertain and it might be better for Ron Paul to drop out and make his views clear.
Could Romney get to the magic number of 1144 before convention time? A crude measure would be looking at his current projected delegate count of 454. Then, add the number of the remaining bound delegates Romney would get if he keeps winning bound delegates at the rate that he has in the past. In that case, he would end up with 1126 delegates. The bottom line is that he would be really happy if someone dropped out.