MONTGOMERY, Ala. » On the first day of April, Zeb Little was sitting down to a barbecue luncheon when he was summoned to a meeting at the state Department of Public Safety. For around 10 minutes, Little, the majority leader in the Democratic-controlled State Senate, waited at the office with several other senior Republican and Democratic lawmakers.

“;And all of a sudden the door opens up, and five agents walk in,”; Little recalled.

The agents, from the Department of Justice, the U.S. Attorney's office and the FBI, said they had found “;substantial evidence of corruption”; surrounding a pending vote in the state Legislature to legalize electronic bingo, and were in the midst of an investigation. Little told them this seemed to be a political maneuver by the bill's opponents to sway the vote. The investigators insisted it was not.

And with that, Alabama learned that its hottest issue—whether electronic bingo is illegal gambling, or a harmless way to raise revenue for governments and charities—had become the subject of a federal criminal investigation. Even by the normally unsightly standards of Alabama politics, the fight had become downright ugly.

Since 2008, Gov. Bob Riley, a Republican who is nearing the end of his second and last term, has been on an aggressive campaign to stop the spread of electronic bingo machines, arguing that they are little more than slot machines and thus illegal under the state Constitution. He set up a task force on gambling, which has been raiding electronic-bingo casinos and carting off the machines in the middle of the night.

Court rulings on the matter, while mostly favorable to the governor's position, have not put the issue to rest, and now state lawmakers have waded in. In March, the state Senate approved a constitutional amendment that would authorize, tax and regulate electronic bingo. The House is scheduled to vote this week, and if it passes, the amendment will be put to a statewide referendum in November.

Proponents of legalizing electronic bingo, mostly Democrats, say that the state needs the money and that gambling needs the regulation. Opponents say the social ills that come with gambling would be costly and end up offsetting the revenues anyway.

Both sides insist that the others are acting at the whim of sinister forces: either the Mississippi and American Indian gambling interests who are eager to stop any competition, or the big money gambling developers who already run casinos and are among the most generous campaign donors in the state.

There is evidence for claims on both sides, though suspicions far outpace fact. In offices and in the hallways of the Statehouse, and along the bar at Bud's, the beer and cigar joint where lobbyists loosen their ties at the end of the day, conspiracy theories about the opposition run rampant. Recently, The Birmingham News reported that some lawmakers had worn recording devices as part of the federal inquiry, which is apparently becoming a common practice in Montgomery.

The disclosure of the federal investigation to legislative leaders has heightened the tension. Even the head of the governor's task force, the district attorney in Mobile, said he had never heard of anything like it. Its timing—two days after the Senate vote and weeks before the House vote—was all too convenient for opponents of the proposal, many Democrats said.

“;Those poor House members down there are scared to death if they vote for this bill,”; said Sen. Bobby Denton, a Democrat and dean of the Senate, who was interviewed for two hours by federal agents at his hotel room the night of the Senate vote. Denton, who had switched his vote from a no to a yes, was grilled after the vote about any connections with gambling lobbyists.

Democrats also point out that the April 1 meeting between the federal agents and the legislative leaders was held in the office of a Riley Cabinet official, and included prosecutors who were involved in the conviction of former Gov. Don Siegelman,a Democrat, which many maintain was politically motivated.

But others say that the involvement of the Justice Department, now under the Obama administration, proves that this is not a partisan fishing expedition. Even some Democrats acknowledge as much.

“;If it was just the Alabama Bureau of Investigation and the U.S. attorney's office, there could be suspicion,”; said Seth Hammett, the speaker of the House and a Democrat, who was at the April 1 meeting. But, he said, “;I don't believe that our United States Department of Justice is going to take sides in this issue.”;

Doug Jones, a former U.S. attorney and now a lawyer representing the state House and Senate Democratic caucuses, raised questions about the meeting in several letters to the Justice Department. In a response to Jones, the acting chief of the department's Public Integrity Section said that the disclosure was “;not unusual”; and that legislators typically found it “;valuable to learn about possible threats to the integrity of their proceedings.”;

Riley has denied knowing about the investigation until after the meeting took place.

Since the meeting, Paul Sanford, a Republican state senator who is against the amendment, has told reporters that he got a call from a lobbyist who represents gambling interests during his campaign last summer.

“;I have two clients right now that are each willing to write you a check for $125,000,”; Sanford recalled the man saying. The clients just needed to know how he planned to vote on the bingo bill. “;We didn't think a whole lot about it at the time,”; Sanford said.

The fight in the Legislature is only part of the fracas. There is plenty going on within the executive branch itself.

The governor's task force has attracted a fair amount of skepticism, and not just because its first commander had to step down in January after he admitted to having won $2,300 at a Mississippi casino. Sheriffs and district attorneys in counties with many jobs in the electronic bingo business have challenged the raids in court and even threatened to arrest members of the task force.

The state attorney general, Troy King, a Republican who says there is still legal uncertainty about the machines, has fought fiercely with the governor over the gambling task force, going so far as to accuse Riley of creating a constitutional crisis. A court case, one of many over gambling, is pending on the question.

All of this has been an education for Koven Brown, the newest state representative. Brown, a soft-spoken owner of funeral homes and a Republican, is not a fan of the amendment. But in his two months as a state legislator, he has been shocked by the vitriol surrounding the debate.

“;It's unreal,”; he said, sitting in his bare office and describing a rally about the bill in Montgomery. “;I'm thinking, 'Folks, this is bingo.' “;