How to explain that Polaris is a circumpolar star in the sky of any North America city? Circumpolar star definition: the stars that remain perpetually above horizon.

My explanation: Latitude affects the constellation we see and Polaris(the North star) has altitude of approximately 89.4 degree. For example, in Miami(25 degree latitude) the Polaris is 90-25=65 degree above horizon. This means that for any city above equator, people are able to see the Polaris.

My explanation is verbose and probably incorrect. Could someone provide a valid one?
In Miami, Polaris will be approx 25 degrees above the horizon, not 65. Height above the horizon is equal to the latitude of the observer.  At the North Pole, Polaris is very nearly directly overhead, all the time, because the Earth's axis of rotation points very nearly towards it.

Due to precession, Polaris will not always be so close to where the Earth's axis points.