The reason he did so was also long forgotten, until recently.

The term refers to a proposed change on a bill that sounds friendly but is actually a sly attempt to kill it. Usually, that's by adding a provision that would turn off supporters or make the law vastly more expensive.

The phrase is often heard around the legislature, but when asked, few politicos can explain where it came from. Everyone, it seems, has a different theory -- almost all of them wrong.

After she used the phrase in a recent committee hearing, Rep. Deborah Ross of Raleigh said she thought it referred to the popular belief that catfish live at the bottom of the river -- about where the bill would end up if the catfish amendment passes.

Other legislators and political reporters had their own theories.

One said it came from the notion that the amendment would "gut" the bill, as a fisherman does to a catfish. Another suggested it referred to the way a catfish pulls downward when caught on a baited hook. And another said it was because catfish are slippery and slimy.

Some theories were easily disproved: There was a "catfish amendment" to a federal bill a few years ago but it had nothing to do with the phrase. And one person's suggestion that catfish are inedible was quickly dismissed.

A search of The News & Observer's archives appears to settle the question in favor of a different explanation: It refers to an old Southern joke.

In 1957, Gov. Luther Hodges wanted to raise the minimum wage to 75 cents an hour. One of his key allies in the legislature was Sen. Cutlar Moore, an insurance agent from Lumberton, which has a prime catfishing river flowing through it.

Moore brought the bill before a Senate committee.

Rather than kill it outright, opponents added amendment after amendment to weaken it. They exempted hotel and laundry workers, firms with fewer than five employees, children under 18 and those who worked less than 18 hours a week.

At the end of the hearing, Moore growled that opponents had gutted his bill. He told a joke, which was recorded in an article the next day:

There was a fisherman, he said, who was having difficulty skinning a catfish which squirmed frantically under the knife.

"Finally," Moore said, "this fellow said, 'Hold still little catfish. All I'm going to do is gut you.' "

Former News & Observer reporter Roy Parker Jr., who likely wrote the unsigned story, said Moore and others regularly referred to "catfish amendments" in those days, with the understanding that it came from that joke.

"There was always some guy getting up talking about a catfish amendment," he said. "But Cutlar was the one who got the most mileage out of it."

Over time, the joke was forgotten, but the term stuck around, and not just in North Carolina. Lobbyists in Georgia use the word "catfishing" to describe their attempts to load up a bill with killer amendments. One lobbyist is known by the nickname "Catfish" for his ability to do so.

Even in 1957, the joke had the dust of history on it. It had been told five years earlier in a congressional meeting, and it appears to have been revived about once a decade.

Like an old blues song, it was embroidered by each teller, but remained recognizable.

Sometimes the fisherman nails the catfish to a tree and gets out a butcher knife and pliers. One time it was an Arkansas man cleaning a White River catfish. Often, the fisherman is a young boy.

Where there's catfish, it seems, there is the catfish joke.

And in North Carolina, there is also the catfish amendment.

(Readers of the Under the Dome blog, including Gerry Cohen, Scott Mooneyham, Danny Lineberry, Laura Leslie, Kirk Ross and Elizabeth Ouzts, and researcher Brooke Cain contributed valuable insight to this report.)