The dominant issue in Texas politics this year is not in the oil field, or on the family farm, though both are places of hardship and pain. Rather it is on the second floor of the state capitol, in the office of the governor.

The personality of Mark Wells White Jr., an incumbent Democrat seeking a second four-year term, seems to be the central issue, and the jury is still out on whether that will be his ruin or his salvation.

If any correlation exists between economic prosperity and the longevity of Texas governors, there is scant evidence of it. In 1978, after a period in which Dallas and Houston emerged as world-class centers of commerce, incumbent Gov. Dolph Briscoe could not even win his Democratic primary.

Four years later, Bill Clements, the state's first Republican governor in the 20th century, lost after presiding over a momentous oil boom.

Now comes Mark White, during whose first term the sun has started to set on the Sun Belt. Texas is free-falling into recession, its budget calculated to reach an unprecedented billion-dollar deficit. Even White's latest cost-cutting measures, in which he has asked state agencies to trim 13 percent from operating expenses, will leave the state dangerously short of a balanced budget, according to state accountants. The governor is steadfast in his resolve not to call a special session of the legislature to attempt further solutions.

Yet White, whose personality seems made for good times, is considered an even bet to win again and possibly attain the longest tenure -- eight years -- of any governor in state history. He faces minimal primary opposition this spring. The polls show him running ahead of or even with the three Republicans who want his job: Clements of Dallas, U.S. Rep. Tom Loeffler of Hunt and Kent R. Hance of Lubbock, who left the House and switched parties in pursuit of higher office.

How is that? For one thing, there is a realization that the imminent recession is no more White's doing than the booms were Briscoe's and Clements'. Furthermore, Texans traditionally give their chief executives little power and a lot of grief, a mixture that White may be better suited to handle than his predecessors. He is regarded as a captivating campaigner, with the buoyant, irrepressible optimism of a college kid out on a Friday night.

With the focus on him, rather than the economy, White is afforded the chance to rise or fall on the issue with which he is most closely identified -- education reform. On that issue he has widespread support.

That is not to say that the latest Lone Star governor is held in awe. Mostly because of his title and the geography of national politics, the white-haired White, at age 45, is deemed in national circles as an attractive vice presidential possibility. At home he is afforded no such deference. Several state Democratic officials say they are wrestling with what they see as a moral dilemma: they want White to succeed, but not too much; they are uncertain that his carefree style would be acceptable on a national level.

One opponent in the May primary, A.D. Crowder, has called him a nerd and a slimeball. Teachers have sent him brown paper bags containing bottles of urine samples to indicate their disregard. The capitol press corps has analyzed his record and pronounced him a walking contradiction. Some call him Mr. Weathervane for all of his changes in positions. Others prefer The Human Windsock.

When he campaigned against Clements in 1982, White pledged that he would not raise taxes or college tuition, and that he would cut utility rates. He kept none of those pledges. Now he boasts of the last tax hike's benefits for the state highway system and says he is proud of his elusive moves as governor.

"What do they refer to Tony Dorsett as?" White said in a recent interview at his office. "You know he doesn't only run in one direction all the time. He makes a great football player, though, doesn't he? Huh?"

His changes in direction, White said, reflect practical politics, not weak leadership. "I haven't changed my integrity at all. We've done exactly what we set out to do. Let me say this: We've had to back up and go around the brush two or three times, miss a couple of boulders. But you don't just run straight through this thing. It's not 'Hey diddle-diddle, right up the middle.' You gotta be a little more artful than that, and my head's not that hard."

White has a proclivity for mixed metaphors that feature football jargon, a sweet irony in that, of all the things he has done in four years, he is perhaps best known for taking on the state's high school football establishment. His refusal to back away from the portion of an educational reform package known as No-Pass, No-Play, in which football players, and other extracurricular participants, cannot suit up unless they pass every course, sent the coaches into such a rage that they organized a lobbying group to oppose White's reelection.

That the group is known far and wide as Flunkpac tells which way the wind is blowing on that issue. Texas polls indicate that two of every three voters support No-Pass, No-Play as well as other aspects of the education reform measure enacted during a special session of the last legislature.

White has seen the polls and made them his. He said in the interview that more than anything else he would like to be remembered as the governor who brought academic excellence to Texas. His interest in the issue began modestly enough when, during the 1982 campaign, he promised to give the teachers a hefty pay raise. Soon he discovered that the public schools in Texas were not held in great esteem by those who make the state go, and that his pay-raise promise could be kept only if it caught a ride on a larger package of reforms like a pilot fish swimming alongside a shark.

It is safe to say that most of the teachers whom White started out trying to please have since soured on him. The teacher unions filed suit trying to stop the mandatory statewide tests scheduled for this week, which are another version of No-Pass, No-Play. In this case they are No-Pass, No-Teach. A state judge last week rejected the arguments of the teachers, who say the tests are demeaning and will prove to be discriminatory in that a larger percentage of Hispanic and black teachers will fail, leaving fewer minority role models in the schools. White's standing in the minority communities is still strong, however, because of another aspect of the reform package that directed more state funds to poorer school districts.

White did nothing to improve his relationship with teachers in January when, at a hearing in El Paso, he implied support for drug testing for all teachers. Under intense criticism, White said there was a semantic misunderstanding and that a transcript proved that he never said mandatory testing for all teachers. But he did say that testing of some teachers would be a good idea. Hence the unsolicited urine samples making their way to the capitol.

While acknowledging that others, especially Dallas billionaire H. Ross Perot, played more pivotal roles than he in the creation and passage of the education reform bill, White said he now considers it the centerpiece of his administration.

"What we've done so far is just the beginning," White said. "All we've really done so far with this reform thing is try to get the ship going in the right direction. I've got two or three more plans yet to be revealed that will carry it much further."

White did not detail his secret plans, but said they involved helping underprivileged students continue their educations beyond high school. He said he could expand educational programs, both at the secondary and college levels, despite the state's difficult financial situation. And he insisted that he would never propose a state income tax to help him do it.

"We're not gonna have one. It isn't gonna happen. That's not in the cards," White said. "I would much prefer to be governor of Texas one more term and not be impeached."