RENO -- Running for governor in 1978, Attorney General Robert List found himself sloshing through the treacherous mix of Nevada gambling and politics, a rite of passage here. He had foolishly accepted a free room at a Las Vegas hotel he was investigating. According to List, a mob-connected hotel executive threatened to expose the error and -- unless the candidate helped him get a gaming license -- season the mix with a tall tale about List and some prostitutes.

The fact that List refused and still won the election gives credence to the theory that public servants can act responsibly -- and survive -- in this neon Gomorrah. But it is hard to keep one's re'sume' clean, no matter how close you stick to the rules -- thus the short, melancholy story of Paul Laxalt's campaign for the presidency.

Can an American politician, in a era when more than half the U.S. population live in states with legal lotteries, maintain friendly ties with the gambling industry and still have a chance for national office?

In only Nevada and New Jersey do legal casinos produce enough money to interest politicians and make this an issue. But games of chance continue to seep into the crevices of local government finance, and their spread throughout most of the nation seems inevitable. Nevada merits a closer look.

Late at night after a few drinks, Nevadans quote Nick Civella, the late Kansas City crime boss: "In time, everyone out there, the fishes out there, gets corrupted. They can't help it. You know, they live right in the midst of it."

But many knowledgeable people here see the gambling industry rapidly losing its ties with the old gang of Midwest crime bosses and Teamster officials who helped build Nevada's gambling palaces. Leading Democrats, like former gaming commission chairman Paul Bible, dismiss the mob influence charges made against Laxalt, a Republican. It is significant that most of the controversial Laxalt friends or acquaintances are dead or retired. The major Nevada casinos are owned by publicly traded companies now, run by graduates of the Harvard Business School, not the Chicago syndicate.

The conscientious federal investigators and journalists who have devoted their lives to exposing organized crime may uncover a few more big stories. But most of what has been written about Laxalt is little more than old associations and investigations pulled out of the files for one more look. Unless the latest surge of immigrants gives us another unusually cohesive underworld, the material is likely to run very thin.

The satirist C. M. Kornbluth took fear of the mob to its logical extreme in his 1953 novel, "The Syndic." He imagined a United States divvied up between eastern and western crime bosses in a "Treaty of Las Vegas" after the U.S. government, to the relief of its vice-happy citizenry, has been exiled to Iceland.

Legal gambling has worked its way into the fabric of the economy and government here, yet corruption and public immorality seem no more corrosive than in most American cities. If anything, the demands of American business, politics and law have worn down and thinned out the mob, not the other way around.

It is instructive to examine the contributor lists of Nevada politicians -- in a file drawer in the basement of the state capital building in Carson City, or on the computers of the Federal Election Commission.

Morris "Moe" Dalitz, for instance, was identified in a 1978 report by the California Organized Crime Control Commission as a former bootlegger who moved to Las Vegas in the late 1940s and began "investing and supervising organized crime investments in hotel and gambling businesses." Dalitz contributed to several Laxalt campaigns and was always an albatross around the senator's neck, particularly after Laxalt declined several opportunities to denounce the man and give him back his money.

That same Moe Dalitz, according to the FEC, gave $2,000 just last year to the campaign of Sen. Harry Reid, a Democrat who won his old adversary Laxalt's seat after the Republican declined to run for reelection last year. Reid also accepted $1,000 from Dalitz's business partner, Merv Adelson. There have been no significant efforts to accuse Reid of improper association with the mob.

The late Ross Miller, father of Nevada's new lieutenant governor, Bob Miller, was a Riviera Hotel and casino executive who was indicted in 1967 in connection with an alleged skimming operation; the charge was later dismissed. Despite a widespread assumption in Nevada that the elder Miller was connected to organized crime, no one says much about it here. The lieutenant governor, through his spokesman, says he was not involved in his father's business, and that is that. On the contributor lists of Reid, Miller and Gov. Richard Bryan, a Democrat elected last year to a second term, appear names of respectable sons of other Nevada personalities with reputed mob ties. Their money is gratefully accepted.

Film versions of underworld intrigue rarely miss a chance to show an aging Godfather vowing his best and brightest son will go straight. Audiences are expected to chuckle. Nevadans, on the other hand, sense that that is the way the world works, and perhaps they are right.

State and local governments collected more than $12 billion from legal lotteries in fiscal 1986. A majority of Americans have access to them, and legalized casinos may still come to other parts of the country with underfunded governments and stingy taxpayers.

Nevada's present, I'll wager, will become our future. The line between illegal vice and innocent entertainment will grow fuzzy and vanish, and someday the name of a shady casino owner on a presidential hopeful's contributor list -- or his family tree -- will simply add attractive color, no more sinister than the occasional robber baron or horse thief.

The writer is a member of The Post's national news staff.