CHICAGO (NewsNation Now) — Polling data is a big part of every election cycle, but as we saw in 2016, the polls did not provide a clear picture.

The 2020 election is on Tuesday.

Nicholas Marchio, a lead data scientist at the University of Chicago and a former data science engineer for Bernie Sanders’ 2020 campaign joined NewsNation on Friday night. He talked about how valuable polls are and the big trends we could expect on election night.

Watch the full interview in the player above.