South Africa's second all-races election turned out to be the electoral landslide that virtually everyone expected, sweeping the African National Congress to within a hair of the two-thirds parliamentary majority that it sought -- and other parties opposed.

With votes from nearly 85 percent of polling stations counted, election officials announced today that the ruling ANC was returned to power with 65.7 percent of the ballots cast Wednesday, one-half of one percentage point less than needed to give the party enough seats in Parliament to unilaterally amend some portions of South Africa's post-apartheid constitution. A projection by the South Africa Broadcasting Corp. indicated that the ANC would pass the two-thirds mark when the final votes are tallied.

The overwhelming support for the ANC paves the way for the nation's president-in-waiting, Deputy President Thabo Mbeki, to succeed his mentor, President Nelson Mandela, who will retire June 16.

With little doubt that the ANC would stroll to victory, the only electoral suspense had revolved around the margin of victory and whether any of the other parties on the ballot would emerge as a viable opposition party. It doesn't appear that any did; other than the ANC, only the Democratic Party seems likely to finish with double digits.

The ANC's dominance of Parliament since 1994, when the country's first all-races election ended white-minority rule, led other parties to warn during the campaign that a two-thirds majority would be a corrupting influence that puts the ANC in a position to punish whites or to amend the constitution at will. Campaign posters reminded voters that South Africa's struggling neighbor, Zimbabwe, is led by a single political party whose leader, President Robert Mugabe, was a liberation hero 19 years ago but today is viewed by many as an autocrat.

Political analysts say, however, that it is overheated rhetoric to compare Mbeki to Mugabe and that there are no signs that the ANC has any plans to change the constitution -- a document that was practically written by the ANC. Still, several said that the ANC's almost unchallenged legislative authority is not good for a maturing but still young democracy.

"A two-thirds majority is kind of like a credit card," said Shaun McKay, a political analyst for the Center for Policy Studies here. "If you have it, you're tempted to use it."

"No matter how you cut it," said Steven Friedman, another analyst with the center, "it does make party politics much more hollow."

In his acceptance speech today, Mbeki was mindful of the suspicion surrounding the ANC's majority, saying that the party would embrace its new power "without arrogance." More than anything, he said, the voters' overwhelming support was a mandate for the party to continue providing housing and jobs for poor blacks and a device to accelerate the pace of change, which has unfolded more slowly than expected.

"The masses of our people have renewed our mandate to govern," Mbeki said today. "The people have said unequivocally that the ANC leads, and we have now arrived at the moment where we go back to work."

Ryan Coetzee, a spokesman for the Democratic Party, which appears poised to overtake the New National Party as the primary opposition party in Parliament, said that his party's representatives would be assertive.

"We don't buy the ANC's line: `Trust me, I'm a politician,' " Coetzee said. "History tells us that where you have a single-party government, you'll find the tendency towards nepotism, you'll find the tendency towards corruption, and you'll find the tendency to suppress dissenting voices."

"Obviously, sadly, the results show that a lot of people don't feel threatened by the ANC's excessive power," Coetzee said. "Well, we're here to tell them that they're wrong."

The Democratic Party, which as the Progressive Party was the lone parliamentary voice against apartheid for 13 years, ran a distant second to the ANC with 10.2 percent of the vote.

By positioning itself as the defender of white rights, the party essentially siphoned off voters from the New National Party -- successor to the National Party, which created apartheid five decades ago. The New Nationalists accumulated 20.5 percent of the vote in the 1994 elections, but its more conciliatory approach caused it to lose white voters, analysts said today, and it slipped to fourth, recording only 7.5 percent of the vote. The Zulu-based Inkatha Freedom Party was running in third place with 8 percent.

CAPTION: Thabo Mbeki, expected to be South Africa's next president, and his wife, Zanele, dance during an ANC celebration in Midrand, north of Johannesburg.