Cooper released a message Thursday to supporters containing television footage from newscasts reporting decisions by the legislature and Gov. Pat McCrory. He then urged viewers to join his team. Cooper said he'll be "building an organization from the ground up to take back North Carolina."
Cooper already has said he's preparing to run for governor in 2016. Ken Spaulding is also running for the Democratic nomination.
The state Republican Party criticized Cooper's effort, saying he's putting aside attorney general duties for politics almost three years before the next gubernatorial election.