When former Democratic representative Kent Hance jumped parties last spring to run for governor in 1986, he worried about being hanged as an opportunist.

Little did he dream that after just one whirlwind summer as a Republican, the problem would have resolved itself.

Or that, by the time it had, he would wish it hadn't.

Last spring Hance was one of the national Republican Party's premier catches in its self-proclaimed Year of the Switcher. Now, he is the first potential casualty of what might be dubbed the political switch-and-bait.

Hance's switch has helped bait Republicans of longer standing and purer lineage into the governor's race against him. They find no passage in the bible of politics where it is written that the newest member of the church choir gets to be pope right off.

Last month former governor William Clements, 68, the only Republican to occupy the Texas governor's mansion in this century, stunned everyone by coming out of political retirement and announcing for governor. "I think he looked at Hance and Republican Sen. Phil Gramm and said, 'Hey, whose party is this?' " said one party leader, who asked not to be named. (Gramm was a Democratic congressman when he switched parties in 1983, reclaiming his House seat in a special election before running for the Senate the following year.)

Then last week, Rep. Tom Loeffler (R-Tex.), 39, announced that he was ready to give up his No. 3 position in the House minority leadership to try for the governor's office, too.

"Guess that pretty well takes care of the argument that I had anything handed to me," drawled Hance, whose formal announcement is not scheduled for another month.

Hance, 42, gamely insists that he can still win a GOP primary by persuading voters that he would be the most electable candidate. A sizable swath of the state's Republican establishment agrees. His financial backers include Dallas real estate mogul Trammell Crow and banker and Dallas Cowboy owner H.R. (Bum) Bright; his pollster is Lance Tarrance of Houston, and his top campaign adviser is Clements' ex-manager, Jim Francis of Dallas.

But for the moment, gruff-talking, multimillionaire Clements is heavily favored to win a primary that historically draws only 350,000 voters, about 4 percent of the state's electorate.

Democrats here are having a hard time figuring out which prospect tickles them more -- another shot at Clements, whom Gov. Mark White (D) defeated for reelection in 1982 and whom many consider the GOP's can't-lose-in-the-spring/can't-win-in-the-fall candidate, or the simple pleasure of watching a political turncoat like Hance get a rude reception.

"I got to believe old Kent's stomach is a little sore," chortled White shortly after the Clements announcement, "from the dry heaves."

For public consumption, GOP leaders say their contested primary is a welcome sign of coming of age. "There was a time not too long ago the nomination wasn't worth fighting for," state party Chairman George Strake said.

But privately, many worry that it will leave scars. "They've never gone through the business of waging a bitter party fight and then trying to put things back together in the fall," said Rep. Martin Frost (D-Tex.) of Dallas. "Let's see how they do."

The cleavages in the party are less likely to be ideological -- all three candidates are conservatives and state issues rarely have an ideological cast -- than personal and cultural.

Hance is what Gramm likes to call a "redneck Republican," and his strategy will be to persuade rural conservative Democrats to vote for the first time in a GOP primary. That is what the national Republican Party's grass-roots realignment campaign has been about this summer -- and it has been a series of flops. The GOP lost a special Texas congressional election that it had hoped to make a showcase, and it fell well short of its goal of converting 100,000 Democrats in four states.

But for some Republicans, success in such ventures at conversion may be more threatening than failure. "If Hance wins, he and Gramm have taken away the party from the country club boys," said one high-ranking Democrat. "You don't think they like that?"

Tension between old and new is inevitable in a party trying to swell its ranks with switchers. It need not always set off sparks, however.

In Michigan, where Wayne County Executive William Lucas switched parties the week Hance did, the GOP establishment has clutched him to its bosom like a prodigal son. It may help that, as a black, he poses less threat of upsetting long-term party power arrangements. Lucas is the favorite for the GOP gubernatorial nomination next year.

In Florida, when Tampa Mayor Bob Martinez switched to the GOP to run for governor next year, an "Anybody But Martinez" movement cropped up within the party. But he has survived and remains the front-runner for the nomination.

Hance's prospects are more dicey. When he first jumped parties, some conspiracy-minded pols here and in Austin saw an elaborate GOP trap to "neuter" him, to turn him from the most attractive young conservative Democrat in the state into a politician without a party.

Hance says he is sure that was never anyone's intent but less sure whether it may be happening nonetheless. "I'd be hell in the fall, but I just might not be able to find the right primary to get me there," he mused recently. Last year, Hance lost the Democratic Senate nomination by a whisker to a much more liberal candidate, former state senator Lloyd Doggett.

Still, he is pressing on. "Nothing can be tougher than my first race, for the state legislature," he said. "Ran against a 16-year incumbent -- and he had a twin brother who was the sheriff."