Democrats picked up the high-stakes governorships of Florida and Texas in midterm elections yesterday while almost all congressional incumbents, including Sen. Jesse Helms (R-N.C.), survived despite some surprisingly tight contests.

Overall, the elections appeared likely to produce little or no change in the Senate, small Democratic gains in the House and a 97 percent reelection rate for congressional incumbents.

Key gubernatorial races in California and Michigan were too close to call early this morning, but with their victories in Florida and Texas the Democrats had already made significant gains in states where there will be major redistricting battles next year.

The only Senate incumbent who appeared in danger of defeat was Rudy Boschwitz (R-Minn.), who trailed liberal college professor Paul Wellstone (D) by 2 percentage points with just over half the vote counted.

Helms, the pillar of conservatism in the Senate for the past 18 years, defeated former Charlotte mayor Harvey Gantt (D), who was trying to become the first black elected to the Senate from the South since Reconstruction. With almost all votes counted, Helms led, 53 to 47 percent.

"I'm sorry I'm so late, but I've been at home watching the grieving face of Dan Rather," Helms said at a victory celebration. "There is no joy in Mudville tonight. The mighty ultra-liberal establishment . . . and commentators and columnists have struck out again."

In the Massachusetts governor's race, John R. Silber (D) conceded defeat early this morning to William F. Weld (R). In Illinois, Secretary of State Jim Edgar (R) appeared to have squeezed out a gubernatorial victory over Attorney General Neil F. Hartigan (D).

House Minority Whip Newt Gingrich (R-Ga.), who led a GOP rebellion against a federal budget package endorsed by President Bush that included new taxes, was among the incumbents who survived yesterday despite a major scare. He defeated Democrat David Worley (D) by just over 1,000 votes.

In New Jersey, Sen. Bill Bradley (D) barely survived an unexpectedly strong challenge from former public utilities commissioner Christine Todd Whitman, whom he outspent nearly 20 to 1.

Bradley apparently was hurt by voter backlash against a controversial tax program put into effect earlier this year by the state's newly elected Democratic governor, Jim Florio. Bradley never took a position on the taxes, but Whitman relentlessly tied him to them.

The biggest gubernatorial race in the country, in California, was too close to call early this morning as Dianne Feinstein (D) and Sen. Pete Wilson (R) ran neck-and-neck. The race seemed likely to be decided by absentee ballots, which in the past have favored Republican candidates.

In Texas, Republican nominee Clayton Williams conceded defeat to Democratic state Treasurer Ann Richards late last night. As his supporters shouted " '94, '94," Williams said, "I'm an Aggie, but I'm not crazy." At another rally in Austin, Richards held up a T-shirt and declared: "A woman's place is in the dome," a reference to the state capitol.

"Williams was overexposed," Richards adviser George Shipley said last night. "They built up an artifice in their television ads which was at variance with Williams the candidate, who kept making one mistake after another. We exploited those mistakes."

Richards won with a heavy share of women's votes and appeared to benefit from populist economic themes she used in attacking the state's system of insurance regulation, which she said discriminated against working people.

Elsewhere in governors' races, GOP incumbents were knocked off in Florida, Kansas and Rhode Island, while in Michigan the two-term Democratic incumbent, Jim Blanchard, was running slightly ahead of state Senate President John Engler (R).

Voters showed their scorn for the established norms of politics by approving term-limitation measures for state legislators in Colorado and California, according to network exit poll projections, and by electing an independent governor in Connecticut -- former GOP senator Lowell P. Weicker Jr. And in nearby Vermont, the Socialist former mayor of Burlington, Bernard Sanders, knocked off Rep. Peter Smith (R).

But the status quo also had a good day around the country, as the overwhelming majority of senators, governors and House members were reelected despite a sharp downturn in public mood and a palpable voter distaste for politics-as-usual.

"After all the talk about voters' anger and the mess in Washington, the mess in Washington will survive and continue," said Democratic pollster Paul Maslin. Of 406 House incumbents seeking reelection, about a dozen appeared likely to lose.

Many of the incumbents who were reelected by narrow margins seemed relieved to have escaped with their political careers.

"I know you don't think politicians have much to offer," a dazed-looking Bradley told voters in New Jersey. "I understand, I really do . . . However you voted, I'm glad I was there to listen, to hear your anger and try to respond."

Seventy-five percent of the voters polled yesterday said the nation is "seriously off on the wrong track," according to results of an ABC News Election Day survey, with the economy and the Persian Gulf crisis topping the worry list. Sixty-two percent said they trusted the federal government "only some of the time."

One of the most prominent victims of voter restiveness was Florida's Gov. Bob Martinez (R), who was defeated by former senator Lawton Chiles (D) in a campaign marked by Chiles's bid to purge politics of big-money influence by refusing to accept contributions of more than $100.

The Florida race was one of three Sun Belt governorships that were the crown jewels of a midterm election in which voters elected 36 governors, 34 senators, all 435 House members, more than 6,000 state legislators and tens of thousands of local officials. The big three -- Texas, California and Florida -- are expected to gain 14 House seats next year as a result of reapportionment, and in 1992 will account for 40 percent of the electoral votes needed to win the presidency.

The epicenter of the kick-the-bums-out mood that some had projected for yesterday was supposed to have been in Massachusetts, where the economy has collapsed in the past year and voters have been furious with retiring Democratic Gov. Michael S. Dukakis.

Silber, on leave as president of Boston University, was favored early in the heavily Democratic state. His abrasive candor played to the voters' outrage at the state's political establishment, but as the campaign went into its final weeks he lost ground as a result of remarks widely interpreted as derogatory to blacks, women, the elderly and others.

Massachusetts voters also rejected a tax-limitation measure that would have forced draconian rollbacks in state spending -- a measure Weld supported and Silber opposed. "The anger that elected Silber in the primary evolved into a larger sense of anxiety and fear about the economic future," said Democratic pollster Thomas Kiley.

The most unabashed liberal running for Senate yesterday was Wellstone (D), a college professor and community organizer who co-chaired Jesse L. Jackson's 1988 presidential campaign in Minnesota. Wellstone, who was outspent 7 to 1 by two-term incumbent Boschwitz, campaigned in a green-and-white converted school bus that looked like a relic from the 1960s, and his message was built on populist economic themes and anti-political fervor.

All other Senate incumbents won, including Mitch McConnell (R-Ky.), John Kerry (D-Mass.), Mark O. Hatfield (R-Ore.) and appointed Sen. Daniel Akaka (D-Hawaii), all of whom had appeared seriously threatened earlier in the campaign.

While Republicans appeared likely to suffer a small net loss in governorships, they had good news in Ohio, where former Cleveland mayor George Voinovich (R) won the governorship now held by Democrats.

In Nebraska, Gov. Kay Orr (R), who had reneged on a no-new-tax pledge, was narrowly trailing businessman Ben Nelson (D) with 94 percent of the vote counted. In Maine, another GOP incumbent governor, John McKernan, was narrowly leading Rep. Joseph E. Brennan (D), who was trying to win back his old job.

In Kansas, the victory of state Treasurer Joan Finney (D) over Gov. Mike Hayden (R) appeared to have been the result of voter unhappiness over a controversial property tax reevaluation program that resulted in widespread tax increases.

In Rhode Island, businessman Bruce Sundlun (D) captured the governorship on his third try, winning in a landslide over Gov. Edward DiPrete (R), whose state economy was in shambles and whose administration was sullied by allegations of scandal.

New York's Gov. Mario M. Cuomo (D) had no trouble winning reelection over underfinanced opponents from the Conservative, Republican and Right-to-Life parties, but his vote total was 12 percentage points below the record 65 percent he amassed in his first reelection campaign in 1986. Cuomo's state economy has fallen on hard times in the last year, and he pushed through $1.8 billion in mew taxes last spring.

Of the the nearly 250 initiatives on state ballots yesterday, the most closely watched was "Big Green" in California, a sweeping measure designed to protect the environment that started out year well ahead in the polls but appeared headed for defeat last night after a heavily financed advertising campaign in which opponents stressed the high cost of the bill.

Californians also voted on two measures to limit the terms of state legislators. Proposition 131, which would have also called for public financing of state campaigns, appeared headed for defeat, while Proposition 140, which also called for sharp cuts in legislators' staffs and pensions, appeared likely to pass. California Speaker of the House Willie Brown (D) had helped to raise and spend $4 million trying the defeat Prop 140, which imposes lifetime limits of six years in office for state Assembly members and eight years for state senators and statewide officeholders.

The Colorado measure places a 12-year limit on both state legislators and members of Congress. The latter provision is sure to face a constitutional challenge.

As the nation voted yesterday, President Bush returned to Washington after casting his ballot early in the morning in Houston, his legal residence. Bush had campaigned in eight states the final week before the election, including two full days for the GOP ticket in Texas.

The GOP's hope was to win enough seats this year to be in a position to regain control of the Senate in 1992 -- when a vulnerable class of Democrats will be up for reelection -- and to pick up enough House seats to give Bush the sort of governing majority that President Ronald Reagan enjoyed in the early 1980s.

Prior to yesterday's balloting, Democrats held a 55 to 45 edge in the Senate, a 258 to 175 advantage in the House (with two vacancies) and a 29 to 21 lead among governorships. Of the 34 Senate seats at risk yesterday, 16 were held by Democrats and 18 by Republicans. Of the 36 governorships up for grabs, 20 were held by Democrats and 16 by Republicans.