The protections put in place over the last half-century by both political parties to guarantee Americans clean air, clean water and bountiful open space have been coming apart at the seams since President Trump took office. The last few weeks have been particularly brutal for conservationists and, indeed, anyone who believes that big chunks of America’s public lands, however rich they may be in commercial resources, are best left in their natural state. ..But none of these annoying facts can erode Mr. Trump’s belief that, in the continuing tug-of-war between commercial development and environmental protection, the environment has too often gotten the best of it, and the time has come to rebalance the scales. This mind-set is shared by all of Mr. Trump’s appointees who have anything to do with the environment, and it is a virtual copy of the thinking that prevailed among George W. Bush’s policymakers 15 years ago, many of whom have emerged like creatures from the crypt to occupy key positions in the Trump administration.