Ross is the stronger candidate, plus Halter already has the liberal label attached to him from his run against Lincoln 2 years ago. Both Dems are helped by the fact that Hutchinson is a weak candidate, their own Stenberg: blown out 3 times statewide (25, 9, 15) and reliant on the state's heavy GOP tilt plus outside groups to pull him through. While he leads Ross 43-38 and Halter 47-28, I'd expect that to change once the campaign gets underway.
http://talkbusiness.net/2013/02/poll-asa-hutchinson-is-the-front-runner-for-governor-in-2014/