SALT LAKE CITY (AP) — The Republican race to fill the congressional seat abandoned by Utah’s Jason Chaffetz is pitting the state’s GOP establishment against further-right conservatives split over two candidates.

The winner of Tuesday’s primary will be the overwhelming favorite in the November special election in a district where Republican voters outnumber Democrats five-to-one.

The GOP’s more moderate flank has backed Provo Mayor John Curtis, a former Democrat, who initially was leading the race.

The more conservative wing is split between Tanner Ainge (aynj), son of Boston Celtics president Danny Ainge, and Chris Harris, a former state lawmaker backed by Texas Sen. Ted Cruz.

Veteran Utah Republican strategist Boyd Matheson says the race has tightened as Ainge and Herrod have stepped up their campaign attacks.