Democrats widened their 83-seat majority control of the House yesterday and gave Rep. Newt Gingrich (Ga.), the second-ranking Republican leader, the scare of his political life in an election that generally was marked by the continued dominance of incumbents.

Illustrating the quirky nature of a volatile campaign season, Gingrich, one of the House's warriors of the right, fought for survival on the same night that Vermont voters elected the first avowed socialist to serve in the House since 1929.

Gingrich, the fiery conservative who led GOP opposition to the deficit-reduction agreement negotiated by President Bush, was running about 1,000 votes ahead of his Democratic challenger, 32-year-old lawyer David Worley, with 99 percent of the ballots counted.

Worley, who lost to Gingrich in their first contest two years ago by 59 percent to 41 percent, was all but abandoned by Democratic Party chieftains in this year's rematch. But he capitalized on Gingrich's support of a congressional pay raise and the frustration of Eastern Airlines workers who felt the Georgia Republican did not adequately support them in their prolonged strike against management.

In Vermont, former Burlington mayor Bernard Sanders, a socialist who said he would align himself with the House Democratic majority, unseated freshman Republican Rep. Peter Smith.

Other Republican incumbents who lost were Rep. Stan Parris of Virginia, beaten by Alexandria Mayor James P. Moran Jr. (D), and Rep. Bill Grant of Florida, defeated by Pete Peterson, a Democrat and former Air Force officer. Grant was a GOP favorite after he switched parties in 1988.

Rep. Chuck Douglas (R-N.H.) also lost, to Democrat Dick Swett, an architect. Douglas had been a staunch opponent of higher taxes, and had been expected to win reelection. Rep. John Hiler (R-Ind.) was heading toward defeat at the hands of former Democratic congressional aide Tim Roemer.

Democratic casualties included Rep. Roy Dyson of Maryland, defeated by school teacher Wayne T. Gilchrest, and Doug Walgren of Pennsylvania, who was denied an eighth term by Rich Santorum, a Republican lawyer from Pittsburgh. It also appeared that Rep. Robert W. Kastenmeier (D-Wis.), the eighth ranking member of the House, would be denied a 17th term.

Democrats were confident early today that they were headed for a net gain of at least a half-dozen seats in the House, where they held a 258-to-175 advantage before the election. All told, it appeared that only about a dozen House incumbents of both parties would lose out of the 406 seeking reelection, a return rate of about 97 percent.

"It puts us in a real strong position going into reapportionment" in 1992, said Rep. Beryl F. Anthony Jr. (D-Ark.), the head of the Democratic Congressional Campaign Committee.

House Speaker Thomas S. Foley (D-Wash.) said the results showed an "underlying concern" among voters about the direction of the country. "We've gone from a period of exuberance to one of more sober reality."

Republicans have not enjoyed majority status in the House since 1954, and early in this congressional election cycle they had set their sights on winning a dozen or more seats before heading into the 1992 election.

In addition to the GOP incumbents who lost, Democrats won back at least four formerly Republican seats left vacant this year. Democrat John F. Reed defeated Republican Trudy Coxe in the seat formerly held by Rep. Claudine Schneider. In Hawaii, Democrat Neil Abercrombie captured a seat that had been held by the GOP. And former Democratic representative Ray Thornton will return to the House after winning a seat vacated by Republican Rep. Tommy F. Robinson in Arkansas. Democrat William Orton also captured a Utah seat that had been held by retiring Republican Rep. Howard C. Neilson. Democrat John W. Cox Jr. was also leading in an open seat in Illinois formerly held by Republican Rep. Lynn Martin.

However, a bright spot for the GOP was the election of one black Republican, the first since 1932, and the possibility of a second. In Connecticut, Republican Gary Franks, a Waterbury alderman, was the winner against former Democratic representative Toby Moffet in a seat that had been Democratic. And in Cincinnati, former Republican mayor J. Kenneth Blackwell was vying for an open seat.

"We have an excellent opportunity to have our own black caucus," said Edward J. Rollins, co-chairman of the National Republican Congressional Committee.

Republican challengers were also threatening to defeat Rep. Chester G. Atkins (D-Mass.), Rep. Jim Bates (D-Calif.) and Rep. James McClure Clarke (D-N.C.), whose western North Carolina district is known as the "revolving door" district because of its competitive nature during the 1980s.

Democratic prospects this year were buoyed by a decline in Bush's popularity, a sputtering economy and a budget debate in which they positioned their candidates as populist defenders of the middle class.

One potential trouble spot for incumbents was the savings and loan scandal, which was an issue in several races, where challengers accused sitting members of being too cozy with the thrift industry.

Democrats criticized for their S&L ties, however, were faring well. Rep. Doug Barnard Jr. (D-Ga.) won an eighth term handily and Rep. Frank Annunzio (D-Ill.) also won reelection. Among those Republicans heavily criticized were Hiler, an apparent loser in Indiana, and Rep. Charles J. "Chip" Pashayan (R-Calif.) and Rep. Denny Smith (R-Ore.), who was trailing far behind Democrat Mike Kopetski.

Democratic gains in the House were predicted to be far less than the recent historical average for off-year elections, when the party that controls the White House has lost an average of 27 seats since World War II.

Nonetheless, yesterday's modest gains for the Democratic Party represent a setback for the GOP and its goal of capturing control of the House in 1992. It also constitutes a political and governmental rebuff for Bush, who had campaigned aggressively against congressional Democrats the past two weeks, and who may now face a Congress less willing to sustain his vetoes as it did 16 times during the last two years.

Democratic House leaders said said even a small improvement in the party's control could make a key difference on policy disputes with Bush, such as a second attempt to push through the 1990 civil rights bill that the president vetoed.

Though Congress's collective reputation with voters plummeted through autumn as the House and Senate struggled to enact a major deficit-reduction agreement, the vast majority of House incumbents entered a truncated election season in relatively solid shape. Despite anxiety about a restive electorate, most members were expected to prevail by using the many weapons of incumbency at their command.

More than one out of six House incumbents -- a total of 74 -- faced no major party opposition yesterday, and about three-quarters of the 406 seeking reelection were either unopposed or faced opponents with such limited financial resources that there was effectively no challenge. In a study last month, the public interest lobby group Common Cause found that 296 House members were "financially unopposed," meaning they either faced no opponent or a challenger who had raised less than $25,000 by the last reporting period.

"Whatever public anger and anti-incumbent sentiment may exist among citizens around the country, House members are shielded by a wall of political money that makes them nearly invincible," said Common Cause President Fred Wertheimer.

A mid-October Washington Post-ABC News poll showed the dichotomy between an electorate angry at Congress as an institution but still favorably disposed toward individual lawmakers. About 60 percent of the respondents said they disapproved of the job Congress was doing. But the survey demonstrated what has long been a truism: Voters dislike Congress but like their individual representative. In that poll, 64 percent said they approved of their lawmaker's job performance.