The 10 jurists filed a ‘‘friend of the court’’ brief Wednesday supporting Massey Energy in the pending appeal.
Others were filed by attorneys general for seven states, a pair of law professors and the James Madison Center for Free Speech.
Chief Justice Brent Benjamin twice helped overturn a $50 million verdict won against Massey by Harman Mining.
Harman appealed, arguing Benjamin should have recused himself because Massey’s chief executive spent more than $3 million to help get him elected.
More than 45 parties filed briefs supporting Harman, including a group of 27 former justices.