National Nurses United, the largest nurses union in the country, will march and rally for Bernie Sanders outside of Tuesday's Democratic debate in Las Vegas.

Promising a "colorful" rally, the nurses and union organizers will march from the nearby Treasure Island Hotel to the debate site at the Wynn Las Vegas. The event is supposed to be a show of force for Sanders, a candidate the union endorsed in August.

"What they have in common is that he means what he says, and what he does reflects the yearning for change among diverse social movements," said RoseAnn DeMoro, the executive director of the group, who will be in Las Vegas for the debate and rally. "What Bernie's campaign represents is an opportunity to not just speak truth to power, but to join movements together to change our country."