Both Front-Runners Show Broad Appeal, Polls Find : Politics: Bush and Clinton cut into rivals’ bases of support. Brown finds blue-collar audience in Michigan.

Both President Bush and Arkansas Gov. Bill Clinton demonstrated extraordinarily broad appeal across ideological and demographic lines to win their decisive victories in Tuesday’s Midwestern primaries, Times exit polls in Michigan and Illinois found.

In both states, the two front-runners carried virtually every significant segment of the electorate, often by commanding margins, the polls found. The tide propelling Clinton and Bush was so powerful that each made substantial inroads into groups that had previously favored their principal challengers: former Massachusetts Sen. Paul E. Tsongas on the Democratic side and conservative commentator Patrick J. Buchanan in the GOP contest.

These resounding victories are bound to increase speculation among strategists in both parties about the contours of a potential general election between Clinton and Bush. On that front, the polls offer mixed results: They suggest that Democratic primary voters in Michigan have relatively few doubts about Clinton but that somewhat greater concerns remain among Democrats in Illinois.

Still, the surveys offer little support for Tsongas’ argument that he would be a stronger general election candidate against Bush. Among Democratic primary voters Tuesday, Clinton’s showing in a hypothetical election against Bush is as strong as Tsongas’ performance against the President. Likewise, Bush’s advantage over Clinton among Republican primary voters in both states is no greater than his lead over Tsongas.

The Times’ polls, supervised by John Brennan, surveyed 2,561 Democratic and Republican primary voters as they exited 60 polling places in Michigan and 2,778 voters from both parties as they left 60 polling places in Illinois. The polls have a margin of error of plus or minus four percentage points for Democratic samples and plus or minus five percentage points for the Republican samples.

The surveys found that former California Gov. Edmund G. (Jerry) Brown Jr. drew support away from Tsongas in Illinois, primarily attracting the better-educated white voters that have sustained both men through the first month of primaries.

But in Michigan, the surveys found, Brown’s pointed protectionist message attracted a new audience: blue-collar voters. By broadening his appeal to that group, while still running well among the college-educated, he drew equally from Tsongas and Clinton--the first time Brown has cut into the Arkansas governor’s base among men and women who live from paycheck to paycheck.

Brown based his Michigan campaign on opposition to the expedited “fast-track” negotiations of a proposed free-trade agreement with Mexico, which many in Michigan fear will accelerate the loss of manufacturing jobs to areas south of the border; Brown hammered Clinton and Tsongas in a television ad for their support of the accelerated talks.

Brown’s message clearly struck a nerve in Michigan--but it was not sufficient to carry Brown past Clinton, even among the groups most sensitive to it. The four-in-10 voters who cited the candidates’ position “on protecting American jobs” as a major factor in their decision preferred Clinton over Brown by 49% to 34%. Those who cited foreign trade as a major factor in their decision--about one in 12--narrowly favored Clinton.

Clinton carried union households by 52% to 31% over Brown, and blue-collar workers by 54% to 33%. Voters who came from households that contained someone employed in the auto industry also preferred Clinton over Brown by a 5-to-3 margin.

These numbers only hint at the sweep of Clinton’s Michigan victory. Clinton carried at least 47% of the vote among both men and women; union households and non-union households; moderates and conservatives; young voters, middle-aged voters and senior citizens. He carried 72% of black voters and 44% of whites; he won large majorities of voters with a high school education or less and those with some college--and even managed a thin plurality among college graduates of all races. He carried 54% of blue-collar voters, and 46% of white-collar voters.

Moreover, Michigan voters apparently gave little credence to the allegations of personal misconduct levied against Clinton, preferring him by substantial margins over his rivals on a variety of personal characteristics associated with the presidency. Just 8% of Michigan voters cited as a major factor in their decision either the questions about Clinton’s draft status during the Vietnam War or the unsubstantiated allegations of marital infidelity lodged against him, and even they gave Clinton 41% of their votes, more than Brown or Tsongas.

The polls did not ask voters about Brown’s last-minute allegation that Clinton “funneled” Arkansas state business to the law firm in which his wife is a partner. But in Michigan, all of the allegations against Clinton had only limited impact. He ran roughly even with his two competitors among voters who cited “trust” and “convictions” as attributes they admired most in their candidate, and those who cited “ethics” split evenly between Clinton and Tsongas, with Brown lagging.

On other personal measures, Clinton’s showing was even more impressive: He carried more than eight out of 10 of those concerned about electability, nearly seven out of 10 of those who concerned about leadership, almost six out of 10 of those looking for “experience” and just over half of those voters seeking a candidate who can bring “needed change.”

For Tsongas, Michigan represented a nadir from which he may find it virtually impossible to recover. His difficulties attracting blue-collar whites and black voters reached crisis proportions in a state where hard-pressed voters felt little attraction to his calls for sacrifice: Just one out of 20 blacks and one out of eight blue-collar whites backed Tsongas.

Among voters who cited the economy as a major concern, Tsongas won just 18%--less than Brown’s 27% or Clinton’s 51%. Even Tsongas’ core supporters deserted him: He could only manage a three-way split with Clinton and Brown among whites earning $40,000 or more a year and among white college graduates.

In Illinois, Tsongas ran somewhat better, narrowly carrying college graduates. He also carried Illinois voters who cited “trust” and “ethics” as a major factor in their decisions--the latter group by 61% to 20% over Clinton. In other respects, Illinois looked similar to Michigan: Clinton carried 42% of the Illinois white vote, compared with 32% for Tsongas and 20% for Brown.

President Bush’s profile was the inverse of Clinton’s. Bush had virtually no problem in Illinois, but faced a few nagging signs of discontent in Michigan. Still, those were not deep enough to bring Buchanan into contention.

From New Hampshire on, Buchanan’s strength has been almost entirely concentrated among voters who consider the nation to be moving in the wrong direction. But that has been a diminishing asset: Voters in the more recent contests have been somewhat more optimistic about the country’s general direction than Republicans in New Hampshire.

More important, even those voters who are pessimistic have become less willing to embrace the challenger. Nearly seven out of 10 New Hampshire Republican primary voters said they considered the nation on the wrong track; but the figure was slightly less than six out of 10 in both Michigan and Illinois.

Moreover, in the Midwest, even those disgruntled voters simply did not turn to Buchanan as readily as their counterparts in New Hampshire and Georgia. Republicans who consider the nation on the wrong track gave Buchanan a 15-percentage-point margin over the President in New Hampshire and an eight-point margin in Georgia. But Bush--replicating his performance on Super Tuesday--actually carried those unhappy Republicans by 8 points in Michigan and 23 points in Illinois.

Likewise, in Illinois, even voters who consider themselves worse off financially than four years ago narrowly went with Bush. In Michigan, where economic discontent is sharper, Buchanan narrowly carried that group.

There were other signs that Buchanan’s protectionist message on trade rang a bell for some Michigan voters. Those who cited protecting American jobs as a major factor in their decision--about a fifth of the GOP electorate--gave Buchanan an eight-point margin over the President.

Demographically, the key divide in the GOP race has been between men and women, and Buchanan again stumbled over that gender gap Tuesday.

In both states, Buchanan won just under a third of men but less than a fifth of women.

Times assistant poll director Susan Pinkus contributed to this story.

THE TIMES POLL: Candidates’ Key Support Groups

The Times questioned voters in Illinois and Michigan to determine where candidates’ support lies. The poll is based on interviews with 3,606 Democratic primary voters and 1,733 Republican primary voters at 60 polling places in each state. The chart shows key demographic groups and qualities that most attracted voters to a candidate. DEMOCRATS CLINTON Key supporters: Illinois * 72% Blacks * 63% Income under $20,000 * 62% High school or less Key supporters: Michigan * 72% Blacks * 62% Incomes under $20,000 * 58% High school or less * 54% Blue-collar workers What they like most: Illinois * 79% Electability * 68% Leadership qualities What they like most: Michigan * 82% Electability * 69% Leadership qualities TSONGAS Key supporters: Illinois * 51% Self-described Republicans * 46% Graduate school * 45% Jews What they like most: Michigan * 29% Incomes over $60,000 * 28% College graduates * 26% White-collar workers What they like most: Illinois * 61% His ethics What they like most: Michigan * 36% His ethics * 31% Stands by convictions * 30% Trust him BROWN Key supporters: Illinois * 22% No religion * 19% Income over $60,000 Key supporters: Michigan * 38% No religion * 35% 18-24-year-olds What they like most: Illinois * 39% Not part of Washington Establishment * 35% Against special interests * 30% Views on environment What they like most: Michigan * 57% Against special interests * 49% Views on environment * 41% His values GOP BUSH Key supporters: Illinois * 92% of people who think nation is headed in right direction * 81% Women * 79% Core Republicans Key supporters: Michigan * 87% of people who think nation is headed in right direction * 74% Women What they like most: Illinois * 96% Experience * 95% Leadership in Gulf War What they like most: Michigan * 87% Trust him * 87% Leadership qualities * 81% Education policies BUCHANAN Key supporters: Illinois * 70% of those who disapprove of Bush * 45% Independents * 30% Men Key supporters: Michigan * 37% Union members * 40% Independents * 35% Roman Catholics * 32% Men Important actors: Illinois * 85% Bush’s flip-flop on taxes * 82% Not part of Washington Establishment Important actors: Michigan * 77% Can bring change * 49% Can protect U.S. jobs Brown’s Impact on the Others If Tuesday’s Democratic primary were between just Clinton and Tsongas, those who voted for Brown would have voted for: ILLINOIS Clinton: 29% Tsongas: 45% Would not vote: 26% MICHIGAN Clinton: 34% Tsongas: 38% Would not vote: 28% Source: Los Angeles Times Poll taken March 17, 1992. The margin of error for Democrats is plus or minus 4 percentage points. Republican error margin is plus or minus 5 percentage points.