Paul's Strategy

What's Ron Paul been up to lately in the debates?  He never went after Mitt Romney, and instead, he focused his firepower on whoever at that time was the main challenger to Romney.  Is there a secret blood oath?  Is Romney a closet Paleolibertarian?  Is Ron Paul a closet moderate? 

Pete Spiliakos has the best reasoning I have seen so far on this seemingly weird pact:

Romney is the establishment safe choice and he is actually running to be president.  Ron Paul knows he isn’t “safe”, knows he isn’t getting the establishment nod, and he isn’t going to be president.  What he is trying to be is the conservative alternative in the race and to redefine ”conservative” to include his combination of spending policies, monetary policies, drug policies, foreign policies, etc.  But if he is going to get the real, authentic, liberty-loving, slot (or as much of it as can be gotten), he has to prevent any of the anti-Romneys from establishing themselves as real conservatives.  That means he has to go at Perry, and Gingrich and Santorum depending on who is doing best.  If any of them become the chief alternative to Romney, then Paul is left out in the cold.