In discussions with the White House over the executive order Trump is scheduled to sign on Tuesday, Pruitt successfully argued against including language revoking the agency’s 2009 “endangerment finding,” according to two sources close to the issue.

The endangerment finding declared that greenhouse gas emissions threaten human health and welfare and made EPA legally responsible for regulating carbon dioxide. It later set in motion much of former President Barack Obama’s climate agenda. To many conservative skeptics of mainstream climate science, overturning the finding is an essential first step toward successfully undoing Obama administration climate regulations on everything from power plants to vehicles.

But Pruitt, with the backing of several White House aides, argued in closed-door meetings that the legal hurdles to overturning the finding were massive, and the administration would be setting itself up for a lengthy court battle.

A cadre of conservative climate skeptics are fuming about the decision — expressing their concern to Trump administration officials and arguing Pruitt is setting himself up to run for governor or the Senate.