LITTLE ROCK—Democrat Mark Pryor has won a second term to the United States Senate, defeating a Green Party nominee who was the only candidate to challenge the senator’s re-election bid.

The call was based on an analysis of voter interviews, conducted for The Associated Press by Edison Media Research and Mitofsky International.

Pryor raised $5.6 million for his re-election bid and did not face any challengers in the May primary. Republicans failed to field a candidate against the freshman senator. The only opponent he faced was Green Party nominee Rebekah Kennedy, an attorney from Quitman who had raised $12,000.

Pryor is the son of former Arkansas governor and senator David Pryor. The current senator won his seat in 2002 after unseating incubment Republican Sen. Tim Hutchinson in a costly, high-stakes battle.