Science, not politics, guides environmental policy in his administration, President Barack Obama insists. No, it does not.

Obama’s blatantly political blocking of the proposed Keystone XL pipeline, in order to placate radical environmentalists, already has made that clear. But the point was reinforced last month.

Taxpayers’ best – perhaps only – friends in the executive branch of government are the inspectors general that watch over most federal agencies. They root out waste and fraud and make it known to the public.

Obama’s political operatives in the Environmental Protection Agency have been blocking that process for years. Members of Congress heard about it from Patrick Sullivan, who is assistant EPA inspector general for investigations.

The EPA’s 10-person Office of Homeland Security is run by Obama’s political staff, lawmakers were told. Officials in that office have prevented the inspector general from obtaining information needed in investigations and have forced some EPA employees to sign non-disclosure agreements, Sullivan said.

He complained that the office “has no power whatsoever to tell the Office of Inspector General what it needs to know.” Yet precisely that has been happening – again, for years.

Obama’s administration has been called the most secretive in history. In addition to blocking access to information, the White House has been known to harass journalists. Now we learn the EPA – with a chief watchdog who knows only what the White House chooses – is, in effect, accountable only to Obama and his political aides.

Slanted, not settled, science has been the EPA’s guide. Without an unfettered watchdog at work in the agency, we may have to wait for historians to tell us just how badly Americans have been misled about environmental policy.