Phoenix, Ariz. — To an outsider, Arizona politics seems to spell R-E-P-U-B-L-I-C-A-N, despite a slight Democratic edge in registration.
After all, this is the sun-baked land of retirees and of GOP patriarch, Sen. Barry Goldwater. It's also the only state in the country that has voted Republican in every presidential election since 1948.
It doesn't take long, however, before a visitor discovers that the state can't be so easily lassoed and branded. Politics in the Grand Canyon State is a complex affair, with conservative, yet fiercely independent, Westerners regularly bucking party lines at the ballot box.
Partisan uncertainty is all the more topsy-turvy this November, thanks to the unpredictable voting habits of the thousands of Sunbelt newcomers who have swelled Arizona's electorate by as much as one-third in the past six years.
It's an unpredictability that packs a political wallop, as Arizonans well know. Just two years ago, for example, voters came within one-half of 1 percent of dumping their venerated Republican senator in favor of a political newcomer - a conservative Democrat who painted Mr. Goldwater as a legislator whose time had come and gone. Ironically, during the same election, voters here handed Ronald Reagan one of his widest margins of victories - a healthy 16 percent spread over incumbent Jimmy Carter.
''Arizona is the paradigm of the New West in the sense that everybody's new, '' says Democratic Gov. Bruce E. Babbitt, now running what politicos here say could be a close race for his second full term in office. ''It has an eclectic political atmosphere that fits the Western tradition of pragmatic politics with a lot of emphasis on regional issues.''
Quality of life, say Governor Babbitt and others, is the thread running through the issues that interest voters most - whether the subject is jobs, schools, water, transportation, or growth. Old-timers who long to keep the state as pristine and open as possible find themselves joined by newcomers who are, if anything, say observers, even more zealous about preserving the natural attractions that lured them to the state in the first place.
''Voters here will vote for people likely to preserve their life style,'' notes George Stragalas III, executive director of the state Democratic Party.
The flood of newcomers, who have pushed the state's population to 2.7 million , up from 1 million in the early 1960s, directly challenges assumptions about the power of incumbency. No longer can it be assumed that a legislator who has delivered for years is likely to glide to reelection. Senator Goldwater's near-upset two years ago was due at least in part, say observers, to newcomers who ''had no idea why Barry Goldwater was around,'' in the words of political strategist Richard Mayol.
This year the ''newcomer factor'' is playing a part in the campaign strategy of at least one candidate - conservative Democratic Sen. Dennis DeConcini. He's making a bid for a second six-year term. Although polls show Senator DeConcini leading his opponent, state Rep. Pete Dunn, by as much as 2 to 1, the junior senator is ''running as if he were behind,'' says DeConcini campaign manager Ron Ober.
''We estimate that 30 to 40 percent of the people who will vote in 1982 weren't here in 1976, when Dennis was first elected,'' he says. ''Because he's only been in office in six years, obviously you have to treat newcomers as undecided voters. They don't know you as well.''
Arizona has grown increasingly Republican in recent years in terms of registered voters - the state GOP has closed the Democrats' lead of 110,000 voters in 1976 to a currently estimated edge of 25,000. That narrowing margin has forced most state Democrats to try to distinguish themselves as conservatives who differ from the liberal policies of the national Democratic party.
Nonetheless, say political experts, issues, not partisan labels, continue to sway most voters, particularly newcomers. These observers note, however, that party affiliation still plays an important role in local, vs. statewide, elections.
The retirees who come to Arizona and tend to vote consistently Republican are offset by the waves of young, well-educated - yet conservative - professionals who come to Arizona for service-oriented jobs in industries like high technology , says pollster Earl deBerge, director of the independent Rocky Mountain Poll.
''Many of the newcomers are young and thoughtful. They look at issues,'' he explains. ''They're the ones you don't know about. They cross all over party lines.''