WATCH: Sen. Roy Blunt declares victory in re-election bid

SPRINGFIELD, Mo. - Democrat Jason Kander has conceded the U.S. Senate race in Missouri to Republican incumbent Roy Blunt.

Kander, the Missouri secretary of state, made the concession in a speech to supporters Tuesday night.

The Missouri race had been closely watched, with control of the Senate potentially at stake. National senatorial committees from both parties, along with several political action committees, poured millions of dollars into the campaigns.

Blunt is 66 and served seven terms in the U.S. House before being elected to the Senate in 2010.

Kander passed on seeking re-election as Missouri's secretary of state to make his Senate bid. The 35-year-old former Army intelligence officer was initially considered a longshot candidate, but polls showed the race was close down the stretch.