John Ramey is a Democrat, though he'll be danged if he can say why.

"There's no rhyme or reason for it anymore, except it's all I know," said Ramey, a country lawyer who spent 25 years as chairman of the Hopkins County Democratic Party here in rural northeast Texas.

"We grew up poor, and we got it burned in us pretty good that the Republicans favor the wealthy," he said, smiling through a thick blue haze of Chesterfield smoke. "My daddy would have whipped me if I was anything but a Democrat."

Texas' 1st Congressional District is full of "Daddy-was-a" Democrats like Ramey. Tugged by heritage in one direction, by ideology in another, they have settled into a schizophrenic voting pattern that many seem at a loss to defend.

In presidential ballots, they forsake ancestral ties and vote Republican. In congressional races, they stick easily to daddy's dictums.

At the local level, this is still the one-party South: there hasn't been a serious Republican candidate for Congress (or for any local office) here in Ramey's lifetime.

Not until now. On Saturday, a special election will be held to fill the vacant 1st District seat, and the front-runner among eight candidates is Edd Hargett, a farmer, engineer, political novice, former Texas A & M football star -- and the lone Republican in the field.

To conversion-minded Republicans, the race has become a test tube for grass-roots political realignment. It is being run in the heart of the small-town, Democratic South -- but within a fast-growing, urban, Sun Belt state where realigning forces are in place.

Last year, the GOP picked up four congressional seats in Texas, and this spring, former representative Kent Hance, one of Texas' best known conservative Democrats, jumped to the Republican Party as a prelude to a probable 1986 gubernatorial bid.

Now the GOP target is the 1st District, misshapen like a dinosaur skull to preserve Democratic hegemony and represented for half a century by Wright Patman, the populist scourge of bankers.

"If the Democrats can't hold this district," said Mark Mattox, Hargett's campaign manager, "it says any Republican can win any district in this state."

Sulphur Springs is typical of the district. It's a small (population 15,000) dairy farming town that has never had wealth and has always been suspicious of those who did. "My father-in-law bought two cars in 56 years, both of them used," said Perry Bradley, campaign manager for one of Hargett's opponents. His father-in-law, it should be noted, was the local bank president.

This is a town where old-timers who gather on the courthouse square to talk politics treat the two great Republican "sins" of the past 120 years -- Reconstruction and the Depression -- as if they were last week's headlines.

"When I returned here in 1978, it just wasn't socially acceptable to be a Republican," said David Baucom, an insurance agent who recalls having to drive 60 miles to pick up yard signs for the Republican candidate for governor that year.

But slowly, animosities are fading, and the White House has been the agent of change. President Jimmy Carter carried the county narrowly in 1980, but President Reagan won it big, with 61 percent, in 1984.

"People had been going to the grocery store, and they noticed that everything wasn't five cents more than it was the week before," said Baucom, who became mayor after a nonpartisan city council election in 1982.

Party identification is losing its grip here. Loyalists like Ramey, who say proudly that they have never voted Republican but can't explain why, are becoming a distinct minority.

"I don't vote the party anymore, I vote the man," said Don Deaton, the local barber, to approving nods from three customers.

That troubles Bradley. He worries that disaffection with the national Democratic Party is going to turn Sulphur Springs into a legitimate two-party town.

"We got to say, screw the national party and just take care of our own business or else Republican U.S. Sen. Phil Gramm and those guys are going to convert every white voter worth a damn," he said.

The grass-roots-minded Gramm arranged to have five-term conservative Democratic Rep. Sam Blakeley Hall Jr. appointed a federal judge this spring, creating the vacancy Gramm hopes to fill with a Republican he helped recruit.

The two Democrats given the best chance to prevent the district from electing its first Republican congressman since Reconstruction are Jim Chapman, 39, a former Hopkins County district attorney who is touting his 99 percent conviction rate, and state Rep. Sam Russell, 39, a conservative who is running on his legislative record. Both are being heavily outspent by Hargett, who figures to spend more than $500,000.

Polls show Hargett leading, and the Democrats hope to keep him under 50 percent, forcing a runoff with their top finisher.

Though Republicans are touting this as a "realigning election," Hargett does not go out of his way to advertise his party affiliation. On the other hand, the Democratic candidates do not go out of their way to tell people who they voted for in the last presidential election. Chapman made a point of not answering that question at a recent candidate forum.

Some here think the Democrats are the candidates with more baggage to carry, and they see the movement to the GOP as inevitable.

"Sometimes I wonder why the South just doesn't go Republican all at once and get it over with," said Grady Sellers, 34, a dentist.

Sue West can explain why: switching is traumatic. A dairy farmer's wife, she grew up in a public housing project 100 miles south of here.

"It's the Democrats who built those kinds of project, it's the Democrats who care for people, that's what my granddaddy always taught me to believe," she said.

"But I have seen that care carried to excess," said West, 47. "I have also seen the wild-eyed liberals take over my party, even get their hooks into good men like Jimmy Carter." She singled out for special scorn "women's libbers," who, she said, have "sold the young women of this country a bill of goods."

These feelings nothwithstanding, the first time West voted for a Republican -- President Richard M. Nixon in 1972 -- "it made me physically ill," she said.

It has become a little less painful every time.

West likes Chapman, but she is still leaning toward Hargett.

"The Republican Party is what the Democratic Party used to be -- you know, for the people," she said. "If my granddaddy were alive, I think he'd understand. I think he'd be repulsed by the same things I am."