I agree. There is a wide literature in poli sci about principal-agent / contract theory -- what incentive parties and legislators have to actually implement the

I agree. There is a wide literature in poli sci about principal-agent / contract theory -- what incentive parties and legislators have to actually implement the policies they stand for and how does the incomplete contract of voting actually achieve this (or not). But this is a slightly unrelated question to whether or not people are better at understanding what the parties claim to stand for.