He can't get away with it twice.
Look, most of America understands not wanting to live in Cleveland. This more than anything is why LeBron got away with 'The Decision.' Who wouldn't want to take their talents from Cleveland to South Beach? Sure, it was classlessly done.
Sure, it seemed like the move of a mercenary at best, and the move of a coward at worst. C'mon! Joining a rival's team? Who does that? That's a Four Horsemen move right there. If LeBron had left Cleveland to join Dwyane Wade's team in Milwaukee, he'd have been reviled even more for dumping Cleveland live on TV.
But he went to a city that prides itself on warm weather and fun. It's hard to argue with that, long term, especially since the basketball part of the plan worked too. James and Wade (and Bosh et al) won a title.
James promised more titles, and now that he has a title, Pat Riley's plan of enticing veterans to take less money to play with LeBron and have a title shot is coming to fruition; witness Ray Allen.
Miami will win more titles. Everything is going according to plan. Everything. And people outside the city of Cleveland will forgive LeBron in direct proportion to how many titles he wins.
L.A. is much like Miami. Beautiful people, nice weather, coastline, celebrities, glamour. Star Island and Malibu aren't dissimilar. Celebrities aplenty; Jack Nicholson in the front row instead of Jimmy Buffett. And now Brian Windhorst of ESPN speculates that the Lakers are planning to make a run at LeBron in 2014, when LeBron can opt out of his contract.
Furthermore, Windhorst suggests that LeBron may be ready to move on in 2014, when there will be two more years of mileage on Wade's already-high odometer.
This would be a worse Decision than the first one no matter how many titles the Heat win in the next two years. If LeBron leaves Miami, he will forever be seen as a ring collector at best; a mercenary with no loyalty to fans or friends.
At worst, he will be seen as a coward that runs to teams with established superstars he can hide behind, like the whiny kid on the playground who won't play games unless he gets to be on the same team as the best player.
James was able to leave Cleveland because, subconsciously, the average sports fan empathized with his leaving Cleveland, and that made it easier to forgive his joining an existing star on an already-successful team. If he leaves Miami, with one, two, or three titles, it will ruin his career.
He will be seen forever as a player who was afraid to win without help, afraid to be the alpha dog, afraid to lead. His career will never recover.
In this day, when public perception of an athlete and that athlete's career arc are inseparably fused, he got away with a massive blow to the public perception of him once, and recovered.
But he can't get away with it twice.