It's not a date that sticks in the craw of most Americans, but to a Republican congressional candidate here named Jim Kolbe, Oct. 8, 1982 brings back acutely painful memories.

"That's the day we really lost the '82 election," Kolbe said, referring to his first race for Congress two years ago. "That was the day they announced that unemployment had gone over 10 percent. And when that hit, the Democrats just took over the economic issues."

Economic troubles and the resulting unpopularity of Reaganomics led to Kolbe's 1982 loss -- in a district that was supposed to be safely Republican -- by a thin margin to Rep. James F. McNulty Jr., an amiable, fairly liberal Democrat closely aligned with Rep. Morris K. Udall (D-Ariz.), who represents the adjoining chunk of the Arizona desert.

This year, though, Jim Kolbe is challenging McNulty again. And this year, thanks to the economic upturn and the popularity of President Reagan, Kolbe has a strong chance to become one of those rare challengers who actually unseats an incumbent House member.

The evident reversal of Kolbe's fortunes demonstrates the power of one of the most important rules of modern congressional politics: If at first you don't succeed, run, run again.

All over the country, congressional hopefuls have discovered that persistence can pay off -- that the credibility and name recognition gained in a losing race for Congress can pay off with a victory the second (or sometimes third) time around.

Norman Ornstein, a political scientist at American Enterprise Institute and a compiler of the book "Vital Statistics on Congress," says there has been "a pretty clear trend" in recent years toward second and third efforts by losing candidates. He estimates that more than 50 of the 435 men and women in the House ran and lost at least once before winning their seats.

The paradigm case of the persistent loser who refuses to quit is Sen. William Proxmire (D-Wis.). He entered and lost not one, not two, but three statewide campaigns for governor before he finally won the Senate seat in 1957 in a special election. Today, he is far and away his state's most popular politician.

Because members of Congress have established extensive mechanisms of staff help and media exposure designed to protect incumbents, it is relatively rare for any House incumbent to lose a bid for reelection. Over the past decade more than 95 percent of the incumbents running for a new term have won. This year, according to experts from both parties, only about two dozen incumbents are in serious danger of losing. Half of them are incumbents facing a rematch with the 1982 challenger.

Two of the closest House races in the country this fall feature former Republican members who lost in the 1982 anti-Reaganomics tide and are now challenging the Democrats who unseated them.

The mountains of western North Carolina provide a colorful backdrop to the take-no-prisoners political war between Democratic Rep. James McC. Clarke and former Republican Rep. Bill Hendon.

Hendon, a forceful, aggressive campaigner, is tying himself closely to Reagan and to Sen. Jesse Helms (R-N.C.) in the hope that GOP voters who stayed home in 1982 will come back to the polls this year. The gentle, patrician Clarke is waging a campaign based on his personal popularity and playing down the Democratic Party connection.

In Connecticut, former Republican Rep. Lawrence DiNardis has mounted a similar "Reagan's team" challenge against Rep. Bruce A. Morrison, the Democrat who unseated him two years ago.

Other Democratic incumbents facing tough rematches this year include Illinois freshman Lane A. Evans against Ken McMillan, Oregon's Les AuCoin against Bill Moshofsky, and Ike Andrews of North Carolina against William Cobey.

In the Baltimore suburbs, veteran Democratic Rep. Clarence D. Long faces his toughest race yet against Helen Bentley, who's challenging him for the third time. And Rep. George E. Brown Jr. (D-Calif.) is getting a scare from third-time opponent John Paul Stark.

The eastern half of Idaho is the scene of a furious rematch between Republican Rep. George Hansen, who faces a jail term for false financial disclosure, and Democrat Richard Stallings. Stallings came within 3,000 votes of beating Hansen in 1982.

Stallings says the name recognition he gained in the 1982 race is "an invaluable commodity." On the other hand, Hansen says he's glad he drew Stallings as a rival again this year because "it's easier to go up against a known commodity."

Other Republicans with tough campaigns against second-time-around challengers include Rep. Herbert H. Bateman, running in Tidewater Virginia against John McGlennon; and William W. Franklin, trying to hold his Mississippi seat against black Democrat Robert Clark.

Because local issues are often paramount, every House race is unique. Still, the patterns emerging in the McNulty-Kolbe battle here in Tucson reflect the general tenor of all the rematches this year.

Their district is a new one created after the 1980 census. It was crafted by the Republican state legislature to be a haven for GOP candidates in general and Kolbe in particular.

But in 1982, McNulty, a longtime political veteran here, took advantage of economic dissatisfaction to carry the new district for the Democrats.

Republican Kolbe says the result will be different this year because "this year the economy is plus for us, and this year we've got Ronald Reagan right above us on the ballot."

Like many House Republican challengers, Kolbe has tried to turn this local race into a referendum between Reagan and House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.). "If you want to hear a sure applause line," Kolbe said, "it's when I tell them that my first vote in Congress will be to put in a new speaker in place of Tip O'Neill."

Kolbe repeats Reagan's promise of deficit reductions with no new taxes, and takes great pleasure in excoriating "the Mondale-McNulty approach of higher taxes everywhere you turn."

McNulty agrees that there's a major difference between the 1982 and 1984 campaigns here, but he thinks the difference accrues to his advantage.

"I'll tell you what's different this time," he said in an interview.

"The difference is that this time there's an incumbent. That's an incredible difference," said McNulty. "It gives you name recognition like you'd never have otherwise. It means you've had two years to do a lot of favors for people."

While Kolbe ties himself tightly to Reagan's coattails, McNulty does not refrain from harsh swipes at the president, even though Reagan is sure to carry the district by a wide margin.

McNulty said this week that Reagan's foreign policy "would be a theater of the the absurd if it weren't so dangerous." He called U.S. actions in Central America "a very weird scenario."

"I don't have any problem saying those things about the administration," McNulty said, "because I've been saying them on the floor of the House, too.

"Because that's another thing about being an incumbent -- you have a record in Washington, and you'd better stick with when you get back home."