Since Support anyone who supports the new tax plan has no chance of being elected, and Support anyone who truly understands economics would not support the tax plan, Conclusion only someone who truly understands economics would have any chance of being elected.
To help us understand the argument, we can diagram it out:
P1. chance of being elected → /support tax plan
P2. understands economics → /support tax plan
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C. chance of being elected → understands economics
This makes it easier to spot the flaw: the argument acts as though the two premises chain together to make it necessary that anyone with a chance of being elected understands economics. However, that mixes up the sufficient and necessary conditions of the second premise. For the argument to be valid, it would need to look like this:
P1. chance of being elected → /support tax plan
P2. /support tax plan → understands economics
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C. chance of being elected → understands economics
The reasoning in the argument ██ ██████ ███████ ███ ████████ ███████ ███ ███████████ ████ ████ ██████ ███
truly understand economics ██ ███ ███████ ███ ███ ████
The argument doesn't ignore this possibility, making (A) incorrect. In fact, the
truly understand economics ████ ██ ██████ ██ █████ ███████
The conclusion claims that only people who truly understand economics have a chance of being elected. This is fully consistent with (B)—understanding economics is claimed as a necessary, not sufficient condition. This possibility wouldn't harm the argument, so it's not a flaw to overlook.
For (B) to be correct, the conclusion would need to be based on the idea that anyone who truly understands economics has some chance of being elected.
do not support ███ ███ ████ ████ ██ ██████ ██ █████ ███████
(C) has the same problem as (B): it's fully consistent with the argument, so ignoring this possibility isn't a flaw. The argument says that not supporting the tax plan is necessary to have a chance at being elected. (C) would only be correct if the argument treated it as a sufficient condition.
do not support ███ ███ ████ ██ ███ █████ ██████████ █████████
(D) addresses the argument's sufficient-necessary confusion, and so properly expresses the flaw. The argument acts as though not supporting the tax plan is a sufficient condition for someone to understand economics, even though it's stated as a necessary condition. But that means there could be people who don't support the tax plan and don't understand economics, as (D) says.
This possibility fully aligns with the argument's premises, but contradicts its conclusion. That's why it's a flaw: because it undermines the support that the premises offer to the conclusion.
have no chance ██ █████ ███████ ██ ███ █████ ██████████ █████████
The argument does acknowledge this possibility, making (E) incorrect. The argument concludes that anyone with a chance of being elected must understand economics. (E) just expresses the contrapositive of the conclusion: that anyone who doesn't understand economics has no chance of being elected.
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