As I noted when the 5th Circuit Court of Appeals stayed EPA’s disapproval of Texas’s regional haze 
plan, EPA had pretty much no chance of winning. Although the parties then stayed the litigation to talk settlement, EPA announced yesterday that it was seeking a voluntary remand of the final rule. You don’t have to be privy to any confidential information to draw the conclusion that a certain election on November 8 rather drastically reduced EPA’s leverage in those negotiations. I assume that Texas just pretty much pulled the plug.
EPA’s status report to the Court announcing its intention to seek a voluntary remand says little about EPA’s reasoning – but it says enough:
In light of the Court’s July 15 Opinion and the fact that the parties’ settlement discussions were unsuccessful, EPA intends to seek a voluntary remand of the final rule in this Court.
Translation? We lost the injunction. We were going to lose on the merits. Trump’s victory eliminated any incentive Texas had to compromise. We have no options left. Discretion is the better part of valor.
It looks as though we may have seen the first concrete implications of the election on environmental policy.