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I feel like I have a pretty strong grasp of conditional logic but I am really frustrated with this question. I came across it in the Manhattan guide and their explanations left a little to be desired. (The Manhattan board also did not help.)

I get the setup and everything:
P1: support tax plan --> ~chance (STP --> ~C)
P2: understand econ. --> ~support tax plan (UE --> ~STP)
Conclusion: chance --> understand econ. (C --> UE)

The logic error is reversing that second premise to form the chain: C --> ~STP --> UE. For some reason I can't wrap my brain around what the answer choices mean. The question states the argument is flawed because it "ignores the possibility that some people who..." Each answer choice is some combo of 2 of the 3 elements. A is the only one I am able to rule out because "UE --> ~STP" is the second premise. It seems that B-E are all ignored possibilities.

Anyone? I'm taking the October LSAT and it's my third and final try so I want to understand every single question I'm attempting here.

OK the argument essentially boils down to the point that only people who do not support the tax plan have a chance of being elected. The error in reasoning is that it assumes the only people who do not support the tax plan are those who understand economics. Just because all the economists do not support it does not mean that ONLY economists do not support it.

There can also exist a group of people who do not understand economics while at the same time do not support the tax plan. Maybe it is a group of people whose wives cheated on them with the guy that proposed the tax plan; it doesn't matter. The point is that the group can exist. This is clearly stated in answer D, "the argument ignores the possibility that some people who do not support the tax plan do not truly understand economics."