Judy Woodruff:

We invited Republican leaders from several states to appear tonight, but none was able to join us.

But Americans For Prosperity, which is the libertarian advocacy group backed by the conservative billionaire Charles Koch, has been opposed to the Obama rules and applauded today's move.

Mary Kate Hopkins is the group's policy manager. And she joins me now.

Mary Kate Hopkins, welcome.

You just heard Virginia's attorney general say what the administration is doing is bad for the environment. Just at a moment when climate change is becoming a greater and greater concern, the administration is going in the wrong direction.