EDMOND, Okla. (AP) — Democratic U.S. Rep. Kendra Horn pulled off one of the biggest political upsets in 2018 when she ousted a two-term Republican incumbent.

But Horn won't have the element of surprise in this year's contest against Republican state Sen. Stephanie Bice.

Although Oklahoma has a reputation as a deep-red state, the 5th Congressional District includes the state’s capital of Oklahoma City, which has become younger and more diverse in recent decades.

The race is one of a number of collisions in the Southwest this year between solid conservative political tradition and the increasing leftward drift of large and medium-sized cities.