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

Super Tuesday — the moment the American presidential primaries can, for all intents and purposes, be decided — is next week. And it could be the moment when Hillary Clinton and Donald Trump take an insurmountable lead over their rivals.

Republican primaries and caucuses will be held in 13 states on Tuesday, where about one quarter of all delegates at stake in the national race will be awarded. On the Democratic side, 11 states along with American Samoa will be casting ballots to select about one-fifth of all delegates.

To break down what is going on in the run-up to Super Tuesday, and what it signals for the broader state of American politics, host Éric Grenier is joined by the CBC's senior reporter in Washington, Keith Boag.

Super Tuesday could be a watershed moment for Trump and Clinton. Trump leads in almost all of the states voting next week, and could rack up a significant delegate lead over a divided Republican field. Ted Cruz may win only Texas, if that. Marco Rubio may win no states at all.

With many of the primaries and caucuses taking place in the southern states, Clinton's advantage among African Americans could propel her to some very big victories. Polls suggest her lead in many of these states is in double-digits. After losing to Bernie Sanders in New Hampshire and beating him only by narrow margins in Iowa and Nevada, Clinton's campaign badly needs the boost a series of big victories will give her.

But has Sanders's surprising strength had an impact on how Clinton is running to be president? And what do Trump's repeated victories mean about the mood of the American electorate?

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

You can follow Éric Grenier and Keith Boag on Twitter.