It’s a good rule not to go public with a statement that you’ve been fired from your last job before you announce for statewide office.

But if you’re Joseph Cao, you’re less committed to the rules. You can be forgiven for spurning conventions when you’re a Vietnamese Republican guy who got elected to Congress in a 64 percent black district in New Orleans.

So Cao let it fly yesterday about the same time he leaked word he’ll be taking on Attorney General Buddy Caldwell this fall, disclosing that he’d been fired from his job as a liaison between the Gulf Coast Claims Authority, Kenneth Feinberg’s shop dispensing BP cash to affected parties from the Deepwater Horizon oil spill, and the Vietnamese community in Southeast Louisiana.

Most folks wouldn’t say they got fired from their last job. They’d say something like “I completed my assignment with my former employer and now I’m looking for other opportunities.”

That’s what’s being said here. Except Cao isn’t saying it.

Feinberg is.

“We appreciate all that former Congressman Cao did in assisting the Gulf Coast Claims Facility,” Feinberg said by email Monday. “We have moved on to the next phase in the claims process, and we are grateful for his completing his assignment with us.”

Cao says he got dumped because Feinberg’s crew told him he was “too hands-on.” But he went a little further than that…

Cao pointed out a number of problems with the process, but his recommendations seemed to fall on deaf ears, he said. Top among them was Feinberg’s insistence on using the average of 2008 and 2009 earnings as the basis for estimating what gulf fishers would have earned in 2010 if the oil spill hadn’t ruined the season.

He said the 2008 season was interrupted by Hurricanes Gustav and Ike and that many shrimpers refrained from harvesting during parts of the 2009 season as a part of an organized protest against low-priced Asian imports being dumped on the U.S. market.

“Those are the kinds of decision-making processes I don’t believe they have in place to really understand how the fishing community really lives,” Cao said.

Cao even questioned why he and other “liaisons” were necessary. He said it simply added a layer of bureaucracy when there had been a legion of claims adjusters in place already. The problem was that local claims adjusters were initially prohibited from working through problems with individual claimants.

Let’s say you’re an employer, and you’re looking to hire somebody. And this guy comes in for an interview. You ask him about his last job, after having seen it on his resume and gotten a polite and somewhat positive recommendation from the old employer. And he responds, “Oh, that gig? Yeah, they fired me from that. I told ’em they didn’t know what the hell they were doing. And that they were wasting money paying me in the first place. I don’t think they liked it too much.”

I’ll imagine you might appreciate the honesty. But you might not be so interested in hiring the guy.

So here’s the former congressman’s pitch to unseat Caldwell…

“I believe that the people of the state will support a person with strong convictions and with strong values. And in my two years in Congress, I have shown that I will not compromise my values for political expediency,” said Cao, who said that he believed voters would see Caldwell’s recent switch from the Democratic to Republican Party as a “politically expedient … flip flop.”

Cao went further, though, explaining that compromising his values for political expediency is, more or less, exactly what he did in Washington…

In his two years in Washington, Cao, the first Vietnamese-American elected to Congress, compiled an unusually independent record. Most notably, he was the sole Republican to vote for the House version of health care overhaul. However, Cao ultimately voted against the final version over his objections to abortion language in the bill that emerged from the Senate.

After his defeat, Cao said he was more conservative than indicated by his voting record — including the first health care vote — because he was obliged to represent the district that elected him.

Cao thinks it’ll take a million dollars to knock off Caldwell, a former Democrat who switched parties a couple of months back after joining the multistate lawsuit challenging the constitutionality of Obamacare. He says he can raise it.

One imagines Caldwell is as optimistic as Cao is today.