Attorney General Jim Mattox of Texas had a funny line when he was running for governor in 1990, trying to elbow his way through a Democratic primary against former Gov. Mark White and State Treasurer Ann Richards: “I’m the only candidate in this race proven innocent by a jury of my peers.”

It was both true and uncomfortable. The state’s top legal official had been indicted and acquitted of commercial bribery while in office. Ordinarily, that is the sort of thing that can send an officeholder home, but Mattox won re-election in 1986 and made it all the way to the 1990 Democratic runoff for governor, a race that still stands as a landmark of nastiness in Texas politics.

The current race for attorney general shows few signs of repeating that tone, but questions about one candidate — state Sen. Ken Paxton, R-McKinney — marked the primary campaign and remain an issue ahead of the general election.

Attorneys general like to call themselves law enforcement officers, but that is a forgiving description, akin to calling a pet beagle the guardian of the homestead. The agency is more like a civil law firm with one client, the state of Texas, which does not even require its attorney general to be a lawyer.

But voters have such a requirement, and if the “top law enforcement officer” line did not work in elections, it would fall out of favor. It has not.

White was the attorney general before he was elected governor in 1982. Mattox built a reputation as a rough-and-tumble campaigner when he ran for each of his three terms in Congress and brought that reputation to his 1982 race for attorney general. When he and White were up for re-election in 1986, Mattox had the travails over a commercial bribery charge, prompting some to wonder whether the candidate for governor would hire his mate on the Democratic ticket as a lawyer.

Here we are again, with a state attorney general, Greg Abbott, in the race for governor alongside a legislator who wants to succeed him. Commercial bribery acquittals and pugilistic campaign styles are not on the menu this time; instead, there are Paxton’s violations of state securities laws and his failure to disclose all of his interests in officeholder filings. Paxton easily won the Republican Party’s nomination in last month’s runoff, but he did not erase questions about how he conducts his business.

For Texas Democrats, who are unlikely to win any statewide races without some lucky bounces, this is a twofer. It gives Sam Houston, the Democratic nominee for attorney general, something to talk about for the next five months, and it could limit one of Abbott’s lines of attack on state Sen. Wendy Davis of Fort Worth, his Democratic opponent.

Abbott’s campaign has been asking loudly about Davis’ law practice and whether her public offices, first on the Fort Worth City Council and now in the state Senate, have benefited the public-sector clients of her private-sector firm.

Getting Paxton elected is not Abbott’s job, but if the private dealings of lawyer candidates are an issue in November, what works against a Democrat might also work against a Republican.

Paxton paid a $1,000 fine after the Texas State Securities Board found he was acting as the unregistered representative of an investment adviser. He had revised his state-required personal financial disclosures to reflect interests he had not previously disclosed. Two police associations in his Senate district — McKinney and Allen — withdrew their endorsements, dinging his law-and-order image. His runoff opponent, Dan Branch of Dallas, called him a “lawbreaker” unfit to succeed Abbott in the attorney general’s office.

In spite of it all, Paxton remains the heavy favorite in a state that has a habit of electing Republicans in statewide races.

Thirty years ago, Texas was in the habit of electing mostly Democrats, and Mattox was the beneficiary in spite of uncertainty over his legal ethics. It was always interesting in those days to watch establishment candidates like Lloyd Bentsen and Bill Hobby on stage with a rascal who, it is safe to say, did not run in the same circles as all of the other Democrats on the statewide ticket.

They held hands, reluctantly. Now it is someone else’s turn.