Democrat Adlai E. Stevenson III's second quest for the governorship of Illinois was a shambles today after his handpicked choices to join him at the top of the party's statewide November slate were defeated Tuesday by two far-right candidates.

The two winners were backed by ultraconservative activist Lyndon H. LaRouche Jr. Mark J. Fairchild won the Democratic nomination for lieutenant governor by about 20,000 votes and Janice Hart captured the party's nomination for secretary of state by about 10,000.

Their victories stunned the Stevenson camp and state Democratic leaders, who blamed the results on lack of party effort to get out their regular vote, on various voting blocs displaying their distaste for a famous Chicago political name and on the way the ballot lists the candidates.

The winning candidates had conducted a virtually invisible campaign, and the Stevenson camp had expected easy wins for the slots by its candidates, state Sen. George Sangmeister and Aurelia Pucinski, daughter of one of Chicago's best-known machine politicians, Alderman and former congressman Roman Pucinski.

Stevenson, who coasted to an easy primary victory over another LaRouche candidate in Tuesday's light balloting, remained incommunicado today, closeted with campaign advisers and party officials to weigh exactly how he can continue his campaign against Republican Gov. James R. Thompson, who is seeking a fourth term.

In a statement tonight, Stevenson vowed that "I will never run on a ticket with candidates who espouse the hate-filled folly of Lyndon LaRouche . . . . " Stevenson said he will seek legal ways to get Fairchild and Hart off the Democratic ticket, "to purge these bizarre and dangerous extremists from the ticket."

He said he will do everything possible with other senior party officials "to short-circuit this subversion of our party."

The statement left open the possibility that Stevenson will withdraw and perhaps seek to form a new party. But this would leave the regular Democratic slate without a gubernatorial candidate.

Hart said Stevenson would be "a wimp if he withdraws." She said the primary results are evidence of a voter movement "to expel the traitors from public office."

Starting a new party is no easy matter. The first hurdle would be getting 25,000 valid party formation petitions circulated and signed by late summer.

Said Thompson, "Nobody's unbeatable, nobody has the right to take voters for granted."

But that may be what happened. Stevenson's campaign manager, David Axelrod, conceded to reporters, "We didn't anticipate the problem."

Although nominated independently in the primary, the nominees for governor and lieutenant governor for each party run as a single ticket in the November election under Illinois election laws. The other five statewide constitutional officers -- including secretary of state, controller, treasurer and attorney general -- run separately.

Fairchild, an electrical engineer, told a news conference today that his victory was a "rebellion vote." The electorate, he said, is "sick and tired" of campaigns run like "horse races."

But handicappers trying to fathom his dark-horse win pointed out that he and Hart had run strongly almost everywhere in the state. Several observers suggested that downstaters rejected Pucinski because they unsympathetically equated her surname with Chicago's tangy reputation for ethnic urban politics.

Voters in some inner-city black precincts told reporters today that they voted against Pucinski in retaliation for her father's leadership role in the white-dominated City Council majority that has consistently fought Mayor Harold Washington since his 1983 election as the city's first black mayor.

Indeed, Stevenson's woes overshadowed the continuing uncertainty here over the outcome of the struggle between Washington and his arch-rival, Alderman Edward R. Vrdolyak, who leads the City Council majority, for seven redrawn council seats where special elections were held Tuesday.

Washington candidates for alderman won two of the seats, which is two less than he needs to achieve a 25-to-25 deadlock with the Vrdolyak aldermen on the 50-member council.

Vrdolyak's forces won three seats, leaving him one shy of the 26 he needs to assure his continued control over numerous city agencies and boards that hand out thousands of patronage jobs every year.

Winners remain undetermined in the remaining two seats of the seven wards, which were redrawn under federal court order to increase Hispanic and black representation on the council.

A runoff election appears likely April 29 in the 15th Ward, where no candidate got more than 50 percent of the vote.

A court fight is under way to determine the outcome of the election in the Puerto Rican-dominated 26th Ward, where seven votes separate Vrdolyak's candidate, Manuel Torres, from Washington's, Luis Gutierrez.

Thompson, unopposed in Tuesday's primary for the GOP nomination to an unprecedented fourth term, beat Stevenson in the 1982 gubernatorial election by 5,074 votes out of a total vote of more than 3.6 million.

In Washington, D.C., Democratic Party officials condemned the statewide results in Illinois.

"It is shocking that followers of Lyndon LaRouche have been able to deceive voters in the Illinois primary," said party spokesman Terry Michael. "LaRouche represents the kook fringe of American politics." Michael said LaRouche and his followers had been trying for years "to gain respectability" by falsely portraying themselves as being affiliated with the Democratic Party.

With 99 percent of the statewide balloting counted in unofficial returns, Fairchild had 331,480 votes (52 percent) to 310,510 votes (48 percent) for Stevenson's preferred candidate, Sangmeister.

With 92 percent of the precincts reported, Hart had 321,161 votes (51 percent) to Pucinski's 311,305 votes (49 percent).

The Fairchild and Hart victories represent a high-water mark for LaRouche's National Democratic Policy Committee, which has backed hundreds of candidates in recent years in Democratic Party primary elections and general elections.

A spokesman at the committee's office said no LaRouche-backed office-seeker has won a contested statewide primary. The spokesman said the group is backing at least 700 candidates for local, state and national offices and expects to increase that to more than 1,000 candidates by the Nov. 4 general election.

LaRouche, a former far-left activist, ran for the presidency in 1984, getting 150,000 votes in presidential primaries, according to the Associated Press. Hart denounced The Washington Post in a telephone interview, declaring, "We're going to put you guys on trial for Nuremburg crimes . . . . We are on the warpath, and we are not going to tolerate the media or anybody else standing in the way . . . . We are in the worst strategic crisis in the history of the western alliance . . . . "

She and Fairchild have expressed support for medical tests to screen all Americans for acquired immune deficiency syndrome (AIDS), quarantine of those with the disease until a cure is found and a "full-scale war" on illegal drug use.

Stevenson told a packed news conference tonight: "I blame myself in part, I blame party leaders and the media . . . . These races were written off. We all assumed they'd been won . . . . I'll never take another one for granted . . . . "

Stevenson said his first effort will be to "purge this ticket of candidates who are not true Democrats. If that fails, he said, "there is the possibility of trying to reconstitute the true Democratic Party under a slightly different label . . . . "

He said party lawyers are "investigating whether all the legal requirements were satisfied by these candidates."

Added Sangmeister: "A lot of people felt Fairchild was more of a name to go with than the ethnic Sangmeister . . . .