The CBC Pollcast, hosted by CBC poll analyst Éric Grenier, explores the world of electoral politics, political polls and the trends they reveal.

The next confrontation between Donald Trump and Hillary Clinton will take place on Sunday at Washington University in St. Louis, Missouri.

The first debate did not go very well for Trump. Since that debate, Clinton's lead over the Republican nominee has grown in national polls and her electoral college advantage has solidified. At the second presidential debate, can Trump do anything to turn his campaign around?

And Trump does need to do something. The Presidential Poll Tracker currently shows him behind by more than three points in the popular vote and his electoral college ceiling no higher than 275 — just barely above the 270 votes needed to win the White House.

But his performance on Sunday will not only be judged by voters. The media plays a large role in setting the terms of how a debate performance is interpreted, partly through the lens of polls of debate-watchers. So what's more important: the debate itself, or the aftermath?

Joining podcast host Éric Grenier to discuss the upcoming debate and the role of the media and polls on the U.S. presidential campaign is Matthew Yglesias, co-founder of Vox.

Listen to the full discussion above — or subscribe to the CBC Pollcast and listen to past episodes.

Follow Éric Grenier and Matthew Yglesias on Twitter.