EPA chief Stephen "Stonewall" Johnson hasn't been very cooperative with Congress before, so we're not expecting him to heed the calls of Senate Environment and Public Works Committee members demanding his resignation. This isn't the first time Johnson has been asked to resign, and we have a feeling it might not be the last.

So what inspired Senators Barbara Boxer (D-CA), along with Sheldon Whitehouse (D-RI), Amy Klobuchar, and Frank Lautenberg (D-NJ) to not only tell Johnson to step down, but also ask Attorney General Mukasey to investigate Johnson for lying?

Well, it doesn't seem to be any one thing. Sen. Boxer helpfully outlined some of the "many, many examples," of why Johnson should step down in her press conference yesterday. They include a plethora of less than green policies employed by the EPA under his tenure, the denial of California's Clean Air Act waiver, and failing to appear at several Congressional hearings, including one that was scheduled for this week by the Senate Judiciary Committee. That hearing was canceled because Johnson refused to show up.

Jason Burnett's testified before the committee last week, saying that Johnson folded under pressure from the White House to not grant the California waiver, contradicting Johnson's assertion that the decision was his, and not say, Dick Cheney's.

We're sure Mukasey cares about investigating perjury, but he has his hands a little full over at the DOJ right now, and probably won't be able to get to Boxer's request before around January of 2009-ish. In the mean time, we expect plenty more fodder to leak its way out of the EPA.