A nationally televised game a week ago, a defender tried this and forced him aggressively to his right every time. He still scored an efficient 40+.
that was the Milwaukee Bucks game. They spent the entire game sitting on his left shoulder and inviting him to drive to the right. The most insane overplaying of a hand possible and basically just gifting him free runs into the lane with his right hand. He did have 42 points, but wasn't terribly efficient as it required 30 FGAs and 11 FTAs combined with 9 TOs along the way.
As for Harden himself, he is insanely talented. His balance and handle is almost unmatched but then when you combine the ability to shoot off the dribble including step back shots with deep range and make them at a high rate it is unguardable.
On the other hand, as talented as he is it is almost unwatchable when Houston has the ball because so many of their possessions involve him just dribbling the ball around for 15 seconds with the other players all just standing still waiting for a kickout. Very little movement on the court in comparison to other teams that either move around a lot or pass the ball around a lot (Houston makes the 2nd fewest passes of any team in the league just barely ahead of OKC and miles behind the 3rd worst team) and at a slow pace (3rd slowest pace in the league which is really odd with 7 seconds or less D'Antoni being the coach).