So Romney has won Illinois by more than ten points over Santorum.
Santorum's failure to win Ohio back on Super Tuesday probably marked the end of his chances of winning the nomination through delegates. This defeat likely ends his other option, stopping Romney getting a majority and successfully appealing to unbound delegates. The thing I can't help but wonder, though, is if Santorum himself knows this? He certainly didn't seem to treat Illinois with the importance it deserved, travelling to Puerto Rico (and promptly putting his foot in his mouth). Nate Silver suggested that Santorum might have decided to be an honourable second place, angling for Romney's running mate. Then Santorum accused Romney of lacking a core.
Still, if Santorum really thinks he can still turn things around, I'm not going to complain. I'll just make some more popcorn.