“Politics is more nationalized now,” said John Breaux, a former senator and among the last of the Cajun Democrats who could routinely win statewide.

Mr. Breaux was discussing the state’s politics over lunch at a white-cloth Italian restaurant in Washington, where, like many retired Louisiana legislators, he is a lobbyist. “It used to be folks were not that concerned about what was happening everywhere else; they were concerned about their own state. Now they’re watching Fox News every night. You have an opinion that is national in scope, not Louisiana in scope,” he said.

In states where politics has served as a drab backdrop to daily life, this might not be such a big deal. But politics in Louisiana, which the writer A. J. Liebling once described as having an intensity and complexity matched “only in the republic of Lebanon,” has traditionally taken center stage. Even as it came to be seen as a malevolent force across the South, government remained an organizing part of life here. The state’s old Robin Hood-style populism — in which oil companies were heavily soaked, if otherwise given full rein, while taxpayers were spared — was considered quite agreeable. Spending on education, health care and infrastructure was generous, and the people did not have to pay for it.

“Politicians were allowed to be funny because the idea was they weren’t stealing your money, they were stealing Standard Oil’s money,” said Gov. Bobby Jindal of Louisiana.

This arrangement fell apart after the big oil bust of the 1980s. The shortfall was somewhat remedied by gambling proceeds, sales taxes and income taxes, but these sources brought along with them corruption indictments and antitax crusades. With a major boom in petrochemical activity, the heady days may return. But for now, state services have been cut to the marrow, and a $1.2 billion shortfall may await in next year’s budget.

Even as the economics changed, Louisiana’s politics remained unusual: The state was alone in the Deep South in voting twice for Bill Clinton and is now the only one of the five Deep South states with a Democrat in the Senate.

This distinctiveness endures in part because the state has three broad categories of voters – not two, as in most other Southern states. White Protestants have mostly been reliable conservatives in northern Louisiana. An engaged black electorate in New Orleans and elsewhere forms a Democratic counterweight.

The white Catholic voters spread across southern Louisiana, many of whom identify themselves as Cajun, make up the third, and often electorally decisive, group. This bloc resists ideological labeling. Cajuns are traditional and conservative but, in part because of the history of discrimination against the Cajun culture in Louisiana, can also be receptive to appeals about obligations to the poor and a little more forgiving on matters of personal virtue.