Once again it appears Mitt Romney is heading towards a serious defeat in the South. Ahead of Louisiana’s primary tomorrow Rick Santorum holds an impressive 14 point lead over Romney, according to a new poll by Public Policy Polling.

Rick Santorum is headed for a commanding win in Louisiana on Saturday. We find him with 42% to 28% for Mitt Romney, 18% for Newt Gingrich, 8% for Ron Paul, and 2% for Buddy Roemer.

It’s interesting to look at these numbers in the context of last week’s results in Alabama and Mississippi. Mitt Romney averaged 30% in those two contests, and that’s about where he is here. Rick Santorum and Newt Gingrich combined for 64% in those two contests, and they combine for a relatively similar 60% here. The big difference though is that conservative voters appears to be abandoning Gingrich for Santorum now, and that’s why Louisiana is likely to be much more lopsided than either of last week’s contests were. If Gingrich was completely out of the race Santorum would have a 22 point lead, 53-31, over Romney here with Paul at 11%

The two pieces of good news for Santorum in the poll are that he has a huge lead, and then Gingrich supporters are starting to migrate. For the first time it appears Santorum is finally starting to consolidated the entire anti-Romney vote.

Over the long term Santorum is still going to need a game changer outside of the South. He’ll continue to win primaries because he has a solid coalition among blue collar workers, very conservative voters and Evangelicals. The problem for him, though, is that Romney coalition is modestly larger and that will allow Romney to collect more delegates.