If you want to understand Texas Republicans, forget about the GOP primary race pitting Texas Lt. Gov. David Dewhurst against Tea Party-backed former state Solicitor General Ted Cruz -- the contest spotlighted by the national media.

The most fascinating race in last week's primary was in fact the contest for district attorney in staunchly conservative Williamson County (pop. 422,679), part of the Austin-Round Rock metropolitan area in Central Texas. It pitted long-serving incumbent John Bradley -- a smooth and patrician lawyer endorsed by Gov. Rick Perry -- against Jana Duty, a young county prosecutor whose experience included prosecuting juveniles and dealing with family violence cases.

But unlike the race pitting Cruz against Dewhurst for the seat of retiring Sen. Kay Bailey Hutchison, this contest was pervaded with the sorts of intriguing subplots found in a John Grisham thriller: two brutal murders, a wrongful conviction, and what many voters regarded as the lame excuses given by Bradley -- a former prosecutor of the year -- for keeping an innocent man behind bars.

In short, the race revolved around the case of Michael Morton -- an innocent man wrongly convicted in Williamson County of murdering his wife, Christine, in 1986. Last year, Morton was exonerated by DNA evidence after spending nearly 25 years in prison. Even more shocking, the results of that DNA test enabled police to quickly arrest and charge another man with Christine Morton's murder as well as the subsequent murder in 1988 of another young Austin mother, Debra Baker.  Both were beaten to death in their bedrooms.

The case of Michael Morton electrified Central Texas, highlighted the problems of wrongful convictions in Texas (sometimes by overzealous prosecutors), and cast a long shadow over Williamson County's district attorney's race.

Williamson County prides itself on being tough on crime -- an attitude once personified by Bradley, a tough-on-crime prosecutor whom Gov. Rick Perry appointed in 2001. To be sure, Bradley had nothing to do with Morton's conviction; Morton's lawyers blame that on previous district attorney Ken Anderson whom Gov. Perry appointed to be a district judge in 2002. Anderson is now being investigated by a state "court of inquiry" for allegedly withholding evidence, including an investigator's report that Morton's 3-year-old son, Eric, witnessed a strange man kill his mom after his dad went to work.

Bradley, however, spent six years vigorously fighting efforts by Morton's lawyers to do DNA testing on a blood-stained bandana found near the crime scene. Bradley insisted it was "irrelevant" to the case, but an appeals appeals-court judge finally ordered the testing. The results lead police to Mark Norwood, a dishwasher in nearby Bastrop who had lived in Austin in the mid-1980s. He was charged in the murders of Christine Morton and Debra Baker.

In Williamson County, residents were sickened that an innocent man had spent 25 years in prison -- and angered for Bradley's role in keeping him there. Duty, for her part, said Morton's wrongful conviction on circumstantial evidence convinced her to run for office -- and she built her campaign around the case.

"I was so ashamed that I was from Williamson County because of the shame that case brought on the county," she told the Texas Tribune in a video interview.

Duty faced a formidable opponent. Bradley remained popular despite his missteps in the Morton case. After Gov. Perry appointed him, he had run a contested race for office in 2002. He was re-elected in uncontested races in 2004 and 2008.

"What I was told, repeatedly, was we don't run against incumbents in this county. And I just thought that was kinda crazy because, you know, coming from San Antonio when I moved to Williamson County, I felt like I'd stepped back in time about 50 years with the attitudes here. And so, nobody else would do it, and true to my nature, I said, 'Well, if nobody else will do it, I will.'" 

Pledging to return "honesty and integrity" to the district attorney's office, Duty contended that the district attorney's office still suffered from the same flawed procedures and policies that led to Morton's conviction, despite Bradley's regrets over what happened. "The goal seems to be more about your reputation and your statistics (in winning cases) than in seeking justice," she said.

Bradley's critics also faulted his chairmanship of the state Forensic Science Commission, saying he pushed members to find no misconduct in a controversial arson investigation that led to the execution of Cameron Todd Willingham. He was convicted of murdering his three children, and he maintained his innocence until his death.

In debates between Bradley and Duty, the name "Michael Morton" repeatedly came up -- along with Bradley's lame excuses and apologies for blocking DNA testing. He hadn't wanted testing, he explained, because the bandana was found outside the immediate crime-scene area and, moreover, it might have been contaminated because of improper handling, even if it was connected to the crime.

To the chagrin of many observers, Bradley found his campaign signs sabotaged by somebody dubbed the "Bandana Bandit" -- a trickster who tied red bandanas on Bradley's campaign signs. Duty called her campaign a "grassroots effort which relied on individuals to spread the word to their friends and neighbors that, together, we could make a change."

Since winning his freedom, Michael Morton has largely eschewed the limelight. He  remained silent about the district attorney's race -- even as his shadow hung over it. Duty, once the underdog, ended up getting myriad endorsements from civic groups and law-enforcement associations.  A prominent Tea Party activist, Peggy Venable, observed that Duty as county attorney had kept Williamson County's "good-old boy" system accountable and would do the same as district attorney.

Residents personally affected by Morton's wrongful convictions also offered endorsements. One came from the jury foreman in Morton's trial, Mark Landrumand. Another was from Caitlin Baker, daughter of the young mother whom Mark Norwood is alleged to have murdered while Morton proclaimed his innocence from prison.

Last Tuesday, Duty won 55 percent of the vote to Bradley's 45 percent. She will face Democrat Ken Crain in November.

The Cruz vs. Dewhurst race is headed for a run-off on July 31. But long after that race is over, Texans will be talking about what just happened in Williamson County.