7 Incumbents Reelected to House : Congress: Challengers say they are upbeat because most of the lawmakers won by slimmer margins than they had in 1986.

Northeastern Los Angeles County voters returned seven veteran congressmen to Washington, but the incumbents’ margins of victory have narrowed since 1986 in most cases, giving some challengers hope for the future.

Republican and Democratic challengers alike said they are encouraged by their parties’ gains, and at least one, Republican Jim Salomon, who lost for the second time to Democrat Anthony C. Beilenson, immediately announced that he will run again in 1992.

Incumbents and political analysts attributed the results to various factors, including low turnout, tax increases and the short time incumbents spent campaigning.

“A low voter turnout is traditionally anti-incumbent,” political pollster Arnold Steinberg said.

“I think our percentages have held up very well considering all the factors,” said Republican Carlos J. Moorhead of Glendale, who was elected to a 10th term.

Unofficial totals showed that Moorhead defeated Democrat David Bayer 59.3% to 34.7%. Moorhead’s percent of the vote in 1988 and 1986 were 69.6% and 74%.

Moorhead said he spent only eight days in the district before the election because of the federal budget stalemate.

“I have a letter on my desk from a man who’s totally angry at President Bush because of tax increases I voted against,” he said. “But the man said he was voting against me because of them.”

Bayer said he thinks he showed that a high-energy, grass-roots campaign can be effective, especially if limits are placed on campaign spending.

Bayer’s campaign manager, John Grula, said the low-budget campaign, which had spent just $30,594 heading into the final weeks of the campaign, had established the potential for a future Democratic challenge against Moorhead. Moorhead said he raised $164,871 in 1990 and had $747,679 on hand as of Sept. 30.

Salomon, the only challenger to outspend an incumbent, did so by a sizable margin and said his race against Beilenson in the 23rd Congressional District cost him $450,000. Beilenson reported spending $91,870 as of Sept. 30.

Unofficial results showed Salomon received 33.7% of the vote to Beilenson’s 62.1%. “We expect that when all the absentees are counted that he’ll be down to 61%, which means we will have cut him down even more,” Salomon said.

In 1988, Beilenson won with 63.5% to Salomon’s 33.1%. Beilenson received 66% of the vote in 1986. Beilenson said he was grateful for a solid victory after having been outspent by so much.

In the 21st Congressional District, Democrat Richard Freiman of Agoura Hills, who received 34.5% of the vote to Republican incumbent Elton Gallegly’s 57.9%, said he considers his campaign a victory of sorts.

But he stopped short of committing himself to a rematch with Gallegly. Freiman said he spent about $16,000. Gallegly spent $196,293.

Gallegly received 68% of the vote in 1986 and 69.1% in 1988.

In other races:

* Incumbent Democrat Howard L. Berman of Panorama City won a fifth term with 61.3% of the vote to 34.5% for Republican businessman Roy Dahlson of Van Nuys. Berman slipped 9 percentage points compared with his showing in 1988, when he won 70.3% of the vote. In 1986, he received 65%.

* Incumbent Democrat Henry A. Waxman of Los Angeles won a ninth term with 69.3% of the vote. Republican John N. Cowles captured 25.1% in his second challenge of Waxman. The congressman received 72.3% of the vote in 1988 and 88% in 1986.

* Republican incumbent William M. Thomas of Bakersfield won 59.5% of the vote to Democrat Michael A. Thomas’ 34.9%. Thomas’ totals were 71.1% in 1988 and 73% in 1986.

* Republican incumbent Jerry Lewis of Redlands received 60.4% of the vote to challenger Barry Norton’s 33.1%. Lewis dropped exactly 10 percentage points from his vote total in 1988. In 1986, he won 77% of the vote.

Staff writers Doug Smith and Alan Miller contributed to this story.