It would be a dangerous political liability for any candidate: The possibility that, as governor, Rick Perry presided over the execution of an innocent man

Yet, that's the prospect raised in recent years by several arson experts and exhaustive national media reports in the case of Cameron Todd Willingham. Maintaining his innocence until the end, Willingham was executed in 2004 for the deaths of his three small children in a blaze that destroyed their Corsicana home in 1991.

Media reports by outlets such as the Chicago Tribune and the The New Yorker may have been easy for Perry to dismiss, or ignore. And likewise, perhaps, was last year's investigation by five experts commissioned by the New York-based Innocence Project, which found arson testimony at Willingham's trial to be based on outdated and invalid investigative criteria.

But brushing off the bruising findings of Craig Beyler proved more difficult. Beyler, a nationally known fire science expert, was commissioned not by a newspaper or an advocacy group, but by a state commission chaired by Perry's own political appointee.

So, when Beyler concluded recently there was no credible scientific evidence to support the finding that the Willingham fire was arson, and likened the investigative methods used to folklore and mysticism rather than science, it appears that the governor had to find a way to silence him.

At first, Perry tried to discredit Beyler, using air quotes in an interview with The Dallas Morning News two weeks ago to refer to “latter-day supposed experts” who have cast doubt on Willingham's conviction.

Then, this week, days before Beyler was scheduled to present his findings to the Texas Forensic Science Commission in a public meeting Friday, Perry made a move so blatantly political that it was stunning even for a candidate locked in a tight primary battle.

He canned the commission's chairman, Sam Bassett, his own two-term appointee, and replaced him with a new chairman who promptly canceled Friday's meeting on the Beyler report.

“Is it true?” the Innocence Project's Barry Scheck asked me when I called him for comment, unable to believe it himself.

Scheck likened the move to President Richard Nixon's infamous attempts to oust a special prosecutor investigating Watergate.

“It's a Saturday night massacre, pure and simple,” Scheck said. “If you don't like the evidence, you just get rid of the judges.”

For the record, the commission wasn't even weighing the issue of whether Willingham was wrongfully executed, but simply the validity of the arson testimony in his trial. To be sure, Willingham was an unsavory character, but even the prosecutor in his case, who stands by the conviction, has acknowledged that the forensic report was “undeniably flawed.”

In addition to the dismissal of Sam Bassett, Perry's office also informed two others on the nine-member commission — a prosecutor and a forensics expert — that their services were no longer needed.

Bassett, an Austin defense attorney for 21 years, wouldn't speculate as to Perry's motives, but he told me he'd had previous discussions with Perry staffers who “were concerned about the investigations we were conducting.”

He said he has no regrets and no doubts about Beyler's credibility. Bassett said he hoped the commission would “remain independent of any political or ideological forces from either side,” although he's disappointed that Perry's move will slow down the commission's efforts to shed light on troubling forensics investigations in Willingham's case and others.

“I hope the commission doesn't stop doing its work just because issues might be difficult,” he said. “That's the job we were asked to do.”

It's part of the job we asked Perry to do, too. To uphold the laws of the state, and act in the interest of justice, not against it. To do the right thing, even when it's politically difficult.

Perry's denial of Willingham's request for a stay of execution five years ago is one thing. Yes, Perry should have given the courts time to review reports that raised doubts about evidence in the case.

But the governor's removal of dedicated public servants, apparently for being too diligent, too thorough, in revealing truths that happen to be inconvenient to his re-election bid, is an outrageous affront to the duties of his office.