"There could be half a billion reasons for the concessions President Barack Obama’s clean-power plan made to a defiant energy industry."

The megabillionaire Koch brothers, whose agenda opposes environmental regulation, have a major impact on Republican politics -- including the 2016 presidential race. Their influence is magnified by the big donors they attract to their causes via semiannual retreats like the one that just ended at a luxury resort near Dana Point, Calif. This year, journalists got limited access to the traditionally secret conclave by agreeing not to disclose donors' identities. Now critics are asking whether such rules compromise the integrity of journalism.

"The campaign to stop President Barack Obama's sweeping emissions limits on power plants began taking shape Wednesday, as 16 states asked the government to put the rules on hold while a Senate panel moved to block them."

"A Senate committee voted Wednesday to block implementation of the administration’s climate rule for power plants."

"To comply or not to comply. That’s the question now facing Texas officials regarding the Obama administration’s ambitious Clean Power Plan. The sweeping regulatory initiative, unveiled [Monday] in its final form, aims at transforming the nation’s electricity-production system to slash emissions of climate-disrupting air pollution."

"Top Republican presidential candidates blasted the Obama administration’s landmark climate rule for power plants."

"Lawmakers are primed for a fight over the future of a critical environmental conservation program."

"NEW YORK -- Several news organizations gained rare access Saturday into a private gathering of influential Republican donors hosted by Freedom Partners Chamber of Commerce, a nonprofit organization backed by conservative billionaires Charles and David Koch. But journalists covering the three-day event, held at a luxurious California resort, had to agree to an unusual restriction. They weren’t allowed to report the names of any of the 450 donors attending without the individual’s permission."

"Republican presidential candidate Jeb Bush, who has made varying statements on climate change this year, said Thursday that he believes humans are partly responsible for it. "