The 11th-hour move was confirmed by the Alabama Republican Party’s Reed Phillips by phone Friday afternoon.
The former commissioner has been called a “closet liberal in league with environmentalists” from some quarters, and is likely to be opposed heavily by state-backed utilities like Alabama Power.
Dunn has filed to challenge Cavanaugh, first elected in 2010, in the state’s Republican primary elections.
It was reported as recently as Wednesday that no one would challenge Cavanaugh.
Dunn originally filed for the race in August, but then dropped out on October 26 citing concerns that the utilities would spend “a lot of money” to defeat his bid to return to the commission.
During his time on the commission, Dunn received political pushback for advocating formal rate hearings for Alabama Power, something opposed by fellow commissioners Cavanaugh and Jeremy Oden.
Dunn echoed the call of environmental groups and the AARP in that effort, which opponents feared would create a “judicial setting” requiring all testifiers to retain attorneys. In lieu, several informal hearings were held throughout the state in 2013.
Dunn’s chief of staff David Roundtree has also been criticized among conservatives for perceived stances against the coal industry, which employs thousands of Alabamians.
The video features coal miner John Box telling Dunn, “If you really care about jobs, get out of the way,” in response to a bill proposed by Dunn to ban commissioners from accepting contributions from the industry.
The primaries are set for March 1, 2016 as part of Alabama’s new alignment with the so-called “SEC primary,” by which a new bloc of Southern states is banding together to increase their importance in national elections.
The following post was made by Dunn on his personal Facebook page yesterday, foreshadowing a run:
Dunn could not be contacted for comment at press time.