Dallas County Sheriff Lupe Valdez, considered a slight favorite to win re-election despite a first term plagued by public missteps, faced off against Republican challenger and former Irving Police Chief Lowell Cannaday in their fifth and final debate at the Belo Mansion downtown.

The incumbent, who is very comfortable in these settings, largely played it safe and refrained from criticizing her opponent -- even on his record of supporting a controversial police program in Irving that screens low-level arrestees for immigration status. If that means she feels confident about her prospects, then her opponent must have felt like his time was running out. Throughout the 45-minute debate, Cannaday continually blistered Valdez, sharply criticizing her management of the office including the troubled jail.

“I continue to hear the sheriff talk about improvements in the jail, but with each year that goes by the state fails the Dallas County Jail," he says, referring to how the Texas Commission on Jail Standards has yet to give a passing mark to the facility under her watch. (Compared to just one failure in 20 years under her predecessor.)

Valdez countered that despite such evaluations, she has improved staffing and sanitation at the facility.

"The Department of Justice and the Jail Commission (Texas State Commission on Jail Standards) have complimented us on how quickly we have improved things," she said.

In fact, the DOJ demanded a series of changes at the jail after it launched an investigation of the place at the beginning of 2007 -- and made it a point to single out the facility for unsanitary conditions. On whether or not anyone at the agency complimented the sheriff's office, Cannaday pointed to a Dallas Morning News story in which nobody at the Department of Justice would go on record confirming such praise.

The debate over the jail -- congenial in tone, blistering in words -- set the mood for a debate that teetered between captivating and dull, often switching between the two on a sentence. While Valdez would point to how she made reforms throughout her department -- from the jail to highway patrol -- Cannaday offered detailed arguments on how she fell short of basic standards of competency. Unlike some other interviews with the challenger, in which the former Irving police chief seemed tentative and soft -- and to be honest, a little old -- today he debated like a man who wanted the job.

For example, after Valdez touted her special DUI unit, which she said has made more than 180 arrests during her tenure, Cannaday quipped that amounts to "one arrest every other day."

“Just look at the record," he said later. "Find out how many DUIs have been arrested by the Dallas County Sheriff’s Department ... You tell me if that’s satisfactory.”

Toward the end of the debate, Cannaday assailed Valdez for failing to attend Democratic Commissioner John Wiley Price's weekly briefings on the jail.

“This is the organization that is charting the course for the Dallas County Jail that has failed five times, and she chooses not to make that meeting?" he said. “I know the sheriff has a lot of meetings, everyone has a lot of meetings … but if there are meetings when you should take a leadership role, then you should be there.”

For her part, Valdez didn't explain why she didn't failed to attend Price's briefing, but did talk about why she's never present at weekly Commissioners' Court meetings.

"Ten percent of the work week would be spent if we went to every single commissioners' court meeting," she said, before adding that, in fact, she works at least 60 hours a week. (An aside: this reporter has attended about a dozen commissioners' court meetings. Most were done within two hours.)

In his closing remarks, Cannaday laid out his case against Valdez, making a rather tortured analogy for the lawyers in the audience that made light of the sheriff's struggles to pass a mandatory state law enforcement exam.

“Imagine if you’re the graduate of law school and, after you graduate, you fail the bar twice and pass a third time by one point, and miraculously someone comes along and says, 'That’s great. We’re going to put you in charge of a 2,000-person law firm and with a $135 million budget and expect you to run it," he began. "And for the next three years, you have continued failure, continued failure, and you have the Justice Department in your organization because of activities in your law firm. And all of the sudden you start losing money, your clients start losing money, your law firm’s reputation is out the window. You wouldn’t put up with it for any length of time at all.

“You don’t fire the sheriff; you only get one opportunity every four years to correct mistakes."

In her closing remarks, the sheriff ignored Cannaday's remarks entirely. It's an odd move that seemed borne, rightly or wrongly, of confidence. Instead, Valdez aptly noted how troubled her department was when she was first elected in 2004.

Jim Bowles, her Republican predecessor, handed out contracts to his crooked buddies, demoralized his staff and feuded with the commissioners' court to the point where some of them willfully underfunded the jail. So there was that. But there was still very little Valdez could say to defend her record since then.

“I want you consider the state the Dallas County Jail was in when we went from understaffed and overpopulated to currently meeting legal guidelines," she said.

Of course, that's a very modest benchmark. And state inspectors, who found nine deficiencies at the jail during their last tour, don't seem to think that the facility is meeting their guidelines. But Valdez has a knack for delivering incomplete arguments in a crisp, powerful way. In a way, she's like a Democratic Sarah Palin. And in an increasingly blue Dallas County, that might be good enough.