And to achieve their goals, they have no problem engaging in the scientization of politics - those end-oriented beliefs they use to start with an agenda and keep creating (or cherry-picking) studies until they find something matches it. Declaring water a pollutant is one example and another is their war on energy.
The EPA works for the White House, not the public, so when they declared war on energy in 2009 it was at the request of the administration, which then wasted $72 billion on alternatives that haven't helped anyone and led to a fortune in taxpayer money lost. Like with solar panels (and, oddly, honey) when an existing business is too cheap for a pet project to be forced into viability, the government solution is to make the cost-effective product more expensive.
The new guidelines for coal-fired plants are just such an effort. The EPA says it is worried about global warming, so it is regulating emissions from future coal plants - knowing full well it won't help with emissions. It is just a de facto ban on coal plants with no benefit to the environment.
How so? The new guidelines are impossible to meet without carbon capture and storage; technology we don't even know works yet. That means it would be pointless for a company to even apply to build one and they will stay with the older, less environmental ones. Gain? nothing.
Coal is declining in popularity anyway - while the government was wasting money on magic rocks, the private sector made cleaner natural gas more affordable. As a result, greenhouse gas emissions from energy dropped to early 1990s levels while coal emissions dropped to early 1980s levels. Yes, you can thank Big Oil for helping stop global warming.
But it means we are only thanking the EPA for pointless rules. Banning something knowing it won't do anything to help solve the problem is an intellectual placebo for environmental voters.
This may have weird political implications too. The president says he is a fan of the working man, he spent heavily on government subsidies to lock up union votes during his 2012 reelection campaign. All those union workers in the coal mines, along with the potential union workers that may never get jobs thanks to the president overruling science studies in order to block Keystone XL, can't be happy he is costing them jobs.
Reference: Standards of Performance for Greenhouse Gas Emissions from New Stationary Sources: Electric Utility Generating Units - EPA