Left Lane Loungers are one of the worst things about driving in the US. Spend any time in Europe, especially Germany and the discipline of drivers is very apparent. There is no sense of entitlement to the left lane, no sense of getting there faster than the other drivers and no sense of I'm in control of the road and doing the speed limit so I will just sit here in the left lane.
The other major issue with American drivers is that they are completely unaware of other drivers. They change lanes at the last moment, never use a turn signal, drive in tractor trailer's blind spots, and slam on their brakes at the last moment.
Jalopnik recently published an info-graph showing which states have Left-Lane Passing Laws.
Honestly, I find it disappointing that only 29 states have laws instructing drivers going slower than normal traffic should be in the right lane. Every state should have laws about this. The lack of laws on use of the left lane and passing on the right only encourages bad driving, dangerous situations, traffic jams, accidents and road rage. We need to adopt German's stricter laws prohibiting passing on the right and directly traffic to use a left lane only when passing and returning to the right when completed. Unfortunately, I think the driver-less automated cars will arrive before American drivers learn basic road etiquette. Until then we all must deal with the left lane loungers.