MOBILE, ALA., JULY 30 -- Once every 20 years, the moons and stars of the political universe align this way: a majority of the nation's governors are up for reelection in the same year the census is held.

Nineteen-ninety is such a year, and its significance is keenly understood by elected officials at all levels of government. This November, voters will elect the hands that will draw the maps defining the constituencies for a decade's worth of congressional and state legislative elections.

Given the stakes, Democrats are barely able to contain their excitement about the 36 gubernatorial campaigns now underway. Not only do they seem likely to add to their current 29-21 advantage in governorships, but they just might make gains in two of the three key states that will pick up at least a dozen new congressional seats in the reapportionment that follows this year's census -- Florida and California.

By 1992, nearly one-quarter of all members of the U.S. House of Representatives will hail from California, Florida and Texas. Republican governors (and Democratic legislatures) currently sit in all three state capitols, but Democrats have an even shot at capturing the governorship in California, a better-than-even chance in Florida and an outside -- though dwindling -- hope in Texas.

"It's not inconceivable that after November, all eight of the largest states will have Democratic governors -- which would be important not just for redistricting but for the 1992 presidential campaign," outgoing Ohio Gov. Richard F. Celeste, chairman of the Democratic Governors Association, said in an interview here during the annual meeting of the National Governors Association.

Celeste's goals are considered extravagant by political experts in both parties. "He must have forgotten about his own state," Missouri Gov. John Ashcroft, head of the Republican Governors Association, retorted dryly, referring to Ohio, the largest prize among the five states in which the GOP has a good chance to pick up a Democratic governorship.

Still, Ashcroft knows his party's overall prospects are dicier than the Democrats': "I'm not saying this is a year where the Republicans are likely to make spectacular gains." Part of the GOP concern is that their likely gains tend to be clustered in smaller states, while the Democrats' best hopes are in larger states. "If we lose Florida, it's not going to fly for me to say, 'Yeah, but we won Vermont,' " said Republican Governors Executive Director Michele Davis.

Governors' races -- even more so than contests for federal office -- turn on personality and local circumstance. But as these 36 individual contests unflold, here are some of the dynamics present in many of them:

Incumbency. With voters' anxiety about the economy rising, anger at the savings and loan catastrophe building, and cynicism toward elected officials deepening, plenty of incumbents are wondering how much of an advantage it is to be an incumbent.

"People don't feel very good about their political leaders these days," said Michigan Gov. James J. Blanchard (D), who is seeking a third term. "When George Bush threw away his lips, he further eroded public trust -- not just for Republicans, but possibly for all incumbent politicians."

Blanchard's opponent is GOP State Senate leader John Engler, a fixture in Lansing for the past 20 years. Normally that depth of experience is a plus for a challenger, but Blanchard said he plans to try to play the anti-incumbent strings in reverse: "I am somewhat blessed to have an opponent who has been in the legislature for 20 years."

Nowhere is the incumbency factor more stark than in Arkansas, where Gov. Bill Clinton (D), just 43, is seeking a record fifth term. Prior to 1986, the Arkansas gubernatorial term was two years. Clinton has run a staggering total of 17 political races -- counting primaries, runoffs and general elections -- in Arkansas since 1974, and the only real issue this year is whether his constituents have tired of a governor recently described as "the only man in American politics who's been a rising star for three successive decades."

Clinton, who is said to be considering a bid for the presidency in 1992, calls incumbency an "extra drag" this year, but says he is also counting on the political inexperience of his GOP opponent, businessman Sheffield Nelson, to hinder the challenger.

Taxes and the Economy. Where incumbents are in trouble, weak economies and/or rising taxes are the most common causes; this is true across regional and party lines. But it is also part of a paradox about state government. During the 1980s, virtually all governors raised taxes in one way or another -- in response to cuts in federal programs -- and voters generally tolerated the increases.

"There's an anti-government party in federal elections, but there is really no anti-government party in state elections," said Democratic pollster Geoffrey Garin. "People want their governors to solve problems and provide services, and they know it takes money."

"It's often not taxes, per se, that gets a governor in trouble," concurred GOP consultant Charles Black. "It's the way the governor handles the tax increase -- the kind of taxes he raises, the leadership qualities he shows, the atmospherics."

Redistricting. After this year, 16 to 18 congressional seats will shift from nine Frost Belt states to five Sun Belt states. Both parties agree that the "crown jewel" at the end of this transfer will be California, slated to pick up as many as seven seats and become the largest congressional delegation in history. It could grow to 52 House members.

This spring, California Republicans failed to persuade voters to pass a ballot initiative that would have given control of redistricting to a bipartisan commission. Now they have nightmares that if they lose the governorship, Democrats will do to them in 1990 what they did in 1980 -- gerrymander away GOP chances in a half-dozen congressional districts. "All the chips are on Pete Wilson {who is running against Democrat Dianne Feinstein}, no question about it," said Black. "It's half of the whole ballgame, nationwide."

The nation's eight biggest states -- where most of the exchange of congressional seats will occur -- are currently split evenly in governorships. Democrats stand to hold onto New York and Pennsylvania, are ahead in Michigan and vulnerable in Ohio. Republicans are vulnerable in California and Florida, slightly ahead in Illinois and solidly ahead in Texas.

Abortion. "Six months ago I and a lot of other people would have said abortion would be the dominant issue this year," said the Republican Governors Association's Davis. "Now I'm not so sure. It's an important piece of the puzzle, but it's not overarching."

"They're whistling past the cemetery," retorted Democrat Celeste. He noted that although there is a wide variance of views on abortion among candidates within both parties, the issue is a net plus for Democrats in several critical states -- including Florida and California.

Davis countered that Democrats who have recently switched to an antiabortion stance -- such as Ohio's Democratic gubernatorial contender, Anthony Celebrezze Jr. -- will pay a price. "I shake my head in disbelief that he's planning to make a big issue of abortion," she said. "Let's just say it's not an area where he has a lot of credibility."

"We'll be happy to make Ohio a test case of the abortion issue any day," said Garin, Celebrezze's pollster. "The fact is that there is not a single Republican candidate anywhere in the country who is running an affirmative campaign on the pro-life issue. Not one. What there are is a lot of pro-life Republicans who are doing their best to run away from the choice issue."

Best Bets for Democratic Pick Ups California: Dianne Feinstein has the franchise on charisma and shaking up the staus-quo. Can Sen. Pete Wilson (R) persuade voters that she also represnts risk--and that he's the more competent problem-solver? If not, she's the next governor.

Florida: Wounded by his handling of taxes and abortion, Gov. Bob Martinez (R) is the nation's most vulnerable big state incumbent. But the Democratic primary has gotten fractious, and Martinez has $5 million in the bank to throw at the winner.

Maine: The deteriorating New England economy has put Gov. John R. McKernan Jr. (R) on the defensive. His opponent and predecessor, Rep. Joseph E. Brennan (D), is accusing him of being a big taxer. McKernan is accusing Brennan of being a big spender.

Kansas: The irony here is that the issue that makes Gov. Mike Hayden (R) so vulnerable --a reconfiguration of property taxes that has led to sharply increased appraisals around the state--isn't a good one for his likely Democratic chalenger, former Gov. John Carlin. The reconfiguration was passed during Carlin's tenure. Both men face contested primaries today {Tuesday}.

Nebraska: Gov. Kay Orr (R) is in trouble because she raised taxes after she said she wouldn't and because her leadership style is widely seen as heavy-handed. She has begun to attack her opponent, businessman Ben Nelson (D), for his dealings with businesses involved with junk bonds.

Rhode Island: Gov. Ed DePrite (R), seeking a fourth term, has been hurt by a tax increase and his involvement in a questionable land deal. The polls show him trailing all three of his potential Democratic challengers. The primary is Sept. 11.

Best Bets for Republican Pickups.

Ohio: Cleveland Mayor George Voinovich (R) was supposed to be a strong candidate for U.S. Senate in 1988, but "it was an $8 million dress rehearsal where he learned what not to do," said one GOP operative. This year, running a textbook campaign against ethical abuses and cronyism in Columbus, he has an 8-10 point poll lead over Attorney General Anthony Celebrezze Jr. (D).

Minnesota: Gov. Rudy Perpich (R) has been in office longer than any Minnesota govenor, and his maverick, sometimes flaky leadership style has taken a toll on his popularity. State Aditor Arne Carlson (R), considered his strongest challenger, first must win a crowded Sept. 11 GOP primary.

Oregon: Attorney General Dave Frohnmayer (R) has a big fundraisisng advantage over Secretary of State Barbara Roberts (D), and appears to be better positioned on the spotted owl issue (he's pushing legilsation to save logging jobs) and his opposition to closing the Trojan nuclear plant. She's the better campaigner, though.

Vermont: Gov. Madeleine Kunin's surprise decision not to seek a fourth term has thrown the door wide open to her Republican predecessor, Richard Snelling. The Democratic candiate is State Sen. Peter Welch.

Alaska: In this "year of the woman," can Republican State Senator and 1986 gubernatoiral candidate, Arliss Sturgulewski, win in macho Alaska? She's the favorite in the Aug. 28 GOP primary, and is likely to oppose Lt. Gov. Stephen McAlpine (D) in the fall.

Also Worth Watching

Texas: If Clayton Williams (R)didn't exist, central casting would have invented him. While out-of-staters read mainly about his gaffes, he keeps starring in masterful television commercials that portray him as the quintessential Texas cowboy/entrepreneur. State Treasurer Ann Richards (D), still wounded from a hellish primary, is the underdog.

Illinois: Attorney General Neil Hartigan (D), who trails slightly in the polls, is running against the "12 years and 21 tax increases" of the tenure of retiring Gov. Jim Thompson. The Republican candidate, Secretary of State Jim Edgar, is trying to cut into tradional Democratic constituencies of blacks and labor. The race, quiet so far, should be a squeaker.

Iowa: Two term incumbent Terry Branstad (R) has only a slight lead in the polls over Democratic Speaker of the House Don Avenson in a race that should offer 1990's purest laboratory test of the abortion issue. Branstad is anti-abortion; Avenson supports abortion rights. The state's economy is in good shape.

Connecticut: This has the makings of a three-way train wreck, with former U.S. Sen. Lowell Weicker (R), running as an independent, currently leading in the polls over his two likely opponents--Reps. John Rowland (R) and Bruce Morison (D). Weicker's appeal has always been that of the maverick and gadfly. The question is: in a troubled economy, will voters want a more conventional problem-solver and consensus-builder?

Arizona: Just when the state thought it was rid of him, impeached ex- Gov. Evan Mecham is back--as a candidate in the GOP primary. Businessman Fife Symington (R) is expected o win the Sept. 11 primary, but the turmoil in his party could well help elect the Democrat--Phoenix Mayor Terry Goddard.

Alabama: Paul Hubbert, a former head of the Alabama Education Association, will run a progressive, let's-get-Alabama-moving campaign against Republican incumbent Guy Hunt. Hunt currently leads in the polls, but this race should tighten during the fall.