You can find Judge Bates’ 35-page thoughtful opinion here (via Mike Scarcella). The judge’s main point is that Congress did not intend attorneys fees in cases in which a plaintiff was not enforcing voting rights under the Fifteenth Amendment but instead was seeking to overturn a congressional statute enforcing voting rights.
It seems a sensible result to me, but it raises a number of issues of first impression, so there could be an appeal.