It's the unkindest cut of all for the Kennedy clan -- after Maria was betrayed by Arnold Schwarzenegger, the philanderer is cashing in big on the Kennedy's home turf.
We did some digging ... and found out the Hyannis Port residents care deeply about what Arnold has done behind Maria's back, because the book stores in town have completely sold out of "Total Recall."
In fact, residents were chomping at the bit to get the book, because most of the sales were pre-orders.
In case you didn't know, Hyannis Port is pretty much synonymous with the Kennedy family name. It's where JFK called home, and where Arnold told Maria's mom her daughter had a great ass.