David H. Murdock came here as a capitalist messiah, a multimillionaire financier from Los Angeles who was going to invest a fortune to rescue the struggling Cannon Mills and revitalize Kannapolis, one of the last of the classic "company towns" of the southern textile industry.

But the painful changes he has wrought triggered the largest union organizing campaign in the South in recent years; a campaign that ends Thursday when nearly 11,000 workers cast ballots on whether to join the 350,000-member Amalgamated Clothing and Textile Workers Union.

The bitter 15-month election drive, in a deeply troubled industry threatened by foreign competition, has blended modern techniques like videotapes, prime time TV ads and billboards, with church sermons and emotional themes about unionism and economic survival that are as old as the southern mills.

At home, residents of Kannapolis (from the Greek, meaning "city of looms") turn on Monday Night Football or Johnny Carson, only to see a union TV ad featuring textile workers at the nearby unionized J.P. Stevens plants urging them to vote for the union to improve job security.

At work, Cannon employes are required to stop production for up to an hour to watch company-produced videotapes featuring professional actors portraying anti-union workers and impassioned pleas from Murdock, his voice crackling with emotion as he calls the union "an insidious cancer," an "enemy of this company and country."

"If I determine that Cannon cannot operate competitively," he says, "I can and I will cease to operate Cannon. This is my decision and mine alone, and nobody can stop me, including this union."

"We have been like a family here," said Bobby Joe Kemp, 32, a third-generation Cannon worker. "But now we are like a family pulled apart."

Much has changed here. "Uncle Charlie" Cannon, the mill-town patriarch for 50 years, until his death in 1971, wore overalls and mixed well with his workers, by most accounts. He provided neat little white houses for the workers at monthly rents below $40. For those having financial troubles, a handwritten note from Charlie Cannon was enough to secure a bank loan.

Murdock, 62, a high school dropout who built a fortune on Arizona real estate, controls a far-flung commercial empire stretching from Hawaii's Castle & Cooke to Washington's Hay-Adams Hotel, with operations in 60 countries. Murdock, who does business from a Bel Air, Calif., estate, is a major fund-raiser for the Republican National Committee and has been a key figure in California Republican election campaigns, including Ronald Reagan's.

After buying Cannon Mills for $413 million in 1982, Murdock invested more than $120 million in space-age automation, including Italian air-jet looms that can weave 450 threads per minute. He laid off more than 2,000 workers, cut the pay and hours of thousands more, and sold of many of the 2,500 company-owned workers' houses that were the legacy of the legendary Cannon family.

Murdock moved quickly to begin selling the Cannon houses, giving workers 90 days to decide whether to buy or leave. Hundreds have moved, while hundreds more have purchased their homes at prices averaging $25,000.

"With Mr. Cannon they thought they had a friend," said Thomas Terrill, a University of South Carolina labor historian who has studied the industry. "They identified with him, but it's harder to identify with Mr. Murdock. They probably feel less family loyalty but greater fear."

The contrast between the styles of Cannon and Murdock is symptomatic of the changes in an industry that had been ruled by paternalistic management but has been forced by intense foreign competition to toughen up, Terrill said.

In North Carolina, 65 textile plants have closed and 85,000 textile jobs have been lost in the last decade. Here in Cabarrus County, unemployment hit a state-high of 18 percent during the summer.

"Murdock is playing on fears," said Bruce Raynor, the ACTWU's southern regional director. "He will never close it. He may sell it, but he can't close it because he owes too much" from borrowing to buy the mill, he said.

Murdock's need to pay off huge debts are a major reason for the "squeeze on workers" that prompted the union drive, Raynor said. "If they had a union, they would have a voice" in negotiating protections against such cuts, he said.

North Carolina remains the nation's least unionized state, with less than 10 percent union membership.

A victory here could boost the sagging textile union, which has shrunk with the industry.

Cannon Mills has long been a prized target of unions. ACTWU tried to organize here in 1974 but lost, 55 percent to 45 percent. "They wouldn't listen back then," Raynor said. "If we handed out a blue leaflet criticizing Charlie Cannon, the streets of Kannapolis would turn blue. They'd throw away our leaflets . . . . This time the response is better."

The pro-union message is carried by people like Bobby Joe Kemp, who underwent what he calls a "conversion" from anti-union to pro-union -- and was fired in what ACTWU said was retaliation for union activity. The company denies the allegation.

"My daddy and granddaddy worked here, and I figured we didn't need no union," said Kemp, a six-year employe. "But all these people have been put on short-time [reduced work weeks]. . . and people get harassed by their boss, and they don't have anybody to defend them. I have seen a lot of things happen to people in here."

The anti-union message, carried by workers who wear "No Union" T-shirts and "Union-Buster" badges inside the mill, is that textile workers are lucky to have jobs and that becoming unionized would jeopardize them.

"I've been here 42 years," said Marie Little, 61. "Yes, I have had my pay cut. But I've still got my job. And, no, I don't want a union."

Little, a skilled weaver who earns about $65 a day, used to tend eight high-speed machines. But with a "stretch-out" she must now run 13 and has a higher production quota.