The start of the NASCAR Sprint Cup race Saturday night has been delayed by rain.

Heavy rain drenched the track about 90 minutes before the scheduled start at Richmond International Raceway, and driver introductions were postponed.

Republican presidential candidate Mitt Romney was at a track for the second time this season. His first visit was the season-opening Daytona 500, which was rained out for the first time in history. The 500 ran the next day, and is the only race this season so far to be rescheduled.

NASCAR has had two events this year shortened by rain — Fontana and Pocono.

If Saturday night's race can't go, NASCAR said it will run Sunday at 1 p.m.

The race is the "regular-season" finale and will determine the 12-driver Chase for the Sprint Cup championship field.