Estimating Russia's Influence on Trump Win

While it's clear that Russia supported Trump in the 2016 campaign, it's less clear just how effective Russia's aid was.

Soon after the election, news orgs should have run a poll of Trump voters along the following lines:

Which of these reports about Hillary Clinton did you read/hear?
Followed by a list of false statements about HRC put out by Russian disnfo

Were those reports you read/heard about Hillary Clinton an important factor in your decision to vote for Donald Trump?

A poll like this would at least be a start in gauging the effect of Russian interference in the 2016 election.  This long after the election, results would be fuzzier than if news orgs had been on the ball at the right time.