So Colonel Tom Davis, the head of the Department Public Safety, on whose watch the Governor’s Mansion burned, has announced his resignation. Davis issued a brief statement that read, in its entirety, “After 43 years and 9 months with the Texas Department of Public Safety, I am retiring on Aug. 31, 2008.” It’s about time. It seems to me that the political leadership has been inexplicably complacent about the shortcomings of security at the Governor’s Mansion — despite the fact that Governor Perry is the most security-conscious chief executive in my memory. Clearly, he has been working behind the scenes to get rid of Davis. We still need to know what Perry knew about the security problems at the Mansion and when he knew it. Did DPS inform him about its lack of personnel and its malfunctioning alarm and surveillance equipment? I bet not. If Perry had known, given his concern about security, he would have done something about them. The Legislature is supposed to provide oversight of state agencies. A legislative investigation of DPS’s performance is overdue. Yes, the Sunset Advisory Commission has been scrutinizing DPS, and they have issued a very critical report about the hidebound agency. But they are concerned primarily with management issues. There is no substitute for a public hearing with the narrow focus of what went wrong at the Mansion. Dewhurst and Craddick should create a joint ad hoc committee, as they did when the TYC scandal broke, and appoint members who would ask the tough questions. It’s not too late.