Arizona Sen. Mark Kelly led his Republican rival, venture capitalist Blake Masters, but the race that could determine which party controls the U.S. Senate was too early to call.
Kelly has distanced himself from Democratic President Joe Biden and plays down his party affiliation.
Masters has tried to penetrate Kelly’s independent image, calling him a rubber stamp for Biden.
The Arizona race is one of a handful of contests that Republicans targeted in their bid to take control of what is now a 50-50 Senate.