MSNBC host Chris Hayes explained on his program Thursday how the Bush administration–and specifically former Vice President Dick Cheney’s son-in-law–played a critical role in defeating regulations that would have strengthened federal oversight of chemical plants like the one that exploded and killed 15 people in West, Texas, last week.

During the time his father-in-law was vice president, Philip Perry worked in various governmental entities such as the White House Office of Management and Budget and the Department of Homeland Security. While at these jobs, he was able to successfully block the Environmental Protection Agency from regulating the chemical industry. As general counsel at the DHS in 2007, Perry played a key role in moving the task of regulating chemical plants from the EPA to his own department–a move that favored the chemical industry.

“Basically, in a backroom maneuver, Perry does the chemical industry’s bidding by moving the oversight of this from the EPA, which the chemical industry hates, to DHS, which the chemical industry thinks they can more easily manipulate,” Hayes explained.

As Hayes goes on to point out, the West Fertilizer Plant had been storing more than 1,300 times the amount of potentially explosive ammonium nitrate that would normally trigger oversight by the DHS. Incredibly, however, the DHS wasn’t even aware that the plant existed, according to Democratic Rep. Bennie Thompson of Mississippi.

— Posted by Tracy Bloom.