The first Republican debate of the presidential campaign begins in the swing state of Wisconsin.

Former President Donald Trump - who is the clear front runner - won't be there.

He says he doesn't need to take part, because he's leading the field by so much.

Trump will instead release his interview with former Fox host, Tucker Carlson.

Former campaign manager for Marco Rubio and now managing partner at Firehouse Strategies Matt Terrill told Mike Hosking Trump might not be there, but he'll be a topic of discussion.

He says they'll need to draw contrast with the front runner to break through.

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