His campaign manager says Barack Obama is likely to return to Montana before the state's June 3 primary to campaign for the Democratic presidential nomination. David Plouffe spoke with Montana reporters by conference call Wednesday. He says the Obama campaign continues to talk to the remaining Montana superdelegates, trying to persuade them to support Obama over his rival for the Democratic nomination, Hillary Clinton. Superdelegates are party officials and officeholders. Three of Montana's eight superdelegates have committed for Obama, while some of the remaining superdelegates say they want to see the June 3 primary results before deciding. The Obama campaign announced Wednesday that it's opening two new campaign offices in Montana, in Whitefish and Wolf Point, giving it 12 offices statewide. Former President Bill Clinton will return to Montana on Saturday to campaign for his wife in Bozeman, Lewistown and Miles City. The trip will be Clinton's fourth this year. Presidential hopefuls Hillary Clinton and Barack Obama are battling for the state, which will hold the nation's last primary on June 3. Hillary Clinton has been under increasing pressure to exit the race and allow Democrats to rally behind Sen. Barack Obama, who has the lead in terms of both pledged delegates and superdelegates. At stake in Montana's primary are 16 delegates to the Democratic national convention. Hillary Clinton's campaign did not release the times or specific locations of Saturday's events.