the only thing I know is that the us imposed a huge tax (or started inforcing) on imported (mostly japanese) trucks in 89 this is when you stopped seting 2dr pathfinders, 4runners, and troopers. they were considered trucks, but they werent trucks if they had 4 doors.
Interesting. I did a bit of research on it. Seems like the new Ford Transit Connect is made in Turkey and shipped here with rear seats. Somehow this avoids the chicken tax? maybe its considered a bus or something with the extra seats? dont know.
But when the vehicle arrives in the US, the rear seats are removed, and shredded because its mostly sold as a 2 seat delivery van. This is absurd and a waste of resources. And a good reason why the tax should be eliminated.
Another example is the Sprinter. Completely assembled in germany, then they have to remove the engine to ship to the states where the engine gets re-installed. Ta-da no chicken tax

but a waste of resources and added expense.
Ive read several things about Mahindra trying to avoid the chicken tax. They have mentioned several ideas, from shipping trucks over like the Sprinter (ie missing engines or other parts) to eating the tax to building the trucks from scratch in the US.
Most current thing i read was they were shopping for a US plant to build from scratch. Possibly this is the cause for the delay.
The chicken tax is preventing the import of lots of IMHO awesome vehicles that would be a big seller, but maybe not in the volumes or at a cost that would justify jumping through the added hurdles to get around the tax or ticking of the UAW.
A great example of this is the Toyota HiLux Diesel. Built in Argentina (i believe) and sold in the rest of the world, but not here. Pretty much my dream truck. Not a behemoth like the current USDM Tacoma has become. I know it would be a big hit if it was brought here with the Diesel. Way nicer than this Mahindra.
Another one is the Ranger sold elsewhere made in Brasil or Austrailia (Thailand?). Personally i like the Aussie model more. But both are Really nice design, with the diesel. Way better than the ancient Ranger sold here. Our ranger is something like 10 years on this current design with only a facelift along the way.