Nearly two-thirds of white college graduates backed Clinton in Kentucky. Only in Arkansas have more of them favored Clinton among the 32 states that have held Democratic primaries in which both candidates competed.
Three quarters of whites who have not completed college - a bulwark of Clinton support this year - also backed the New York senator. She has seldom done better this year with those blue-collar white voters - little surprise considering Kentucky has a high proportion of whites and one of the country's highest proportions of non-college-graduates.
In addition, only about four in 10 whites in Kentucky said they would vote for Obama in a matchup with John McCain in the general election. Nearly as many said they would support the Republican, and the rest said they would not vote.
It was not just the voters' race, but their racial attitudes, that proved influential.
About one in five whites said race played a role in choosing a candidate Tuesday - on par with results in several other Southern states. Nearly nine in 10 of that group backed Clinton - the highest proportion yet among the 28 states where that question has been asked in exit polls.
Only three in 10 whites who said race was a factor said they would vote for Obama should he oppose McCain in November. Four in 10 said they would back McCain, while the rest said they wouldn't vote.
Among whites who said race was not a factor in picking a candidate Tuesday, half said they would support Obama over McCain.
Oregon was also voting Tuesday. With its mail balloting still under way Tuesday evening, interviews there showed stark contrasts with Kentucky. Only about one in 10 white voters in Oregon - which is more liberal than Kentucky - said the race of the candidates was important to them.
As the battle for the Democratic nomination finishes its fifth month, there were signs in Kentucky that some voters are looking beyond contest's end. Just over half of voters said they expect Obama to win the party's nomination - including one in three Clinton backers.
Even so, the distaste each candidate's supporters had for the rival contender was clear, underscoring a challenge the party will face in uniting its voters for the fall election.
Only a third of Clinton backers said they would vote for Obama against McCain. Obama voters seemed more forgiving - seven in 10 said they would vote for Clinton.
Just four in 10 Clinton supporters favored picking Obama as running mate should she win the nomination. The same number of Obama backers want Clinton to run as his vice president.
Illustrating Clinton's dominance in Kentucky, only half of those voting Tuesday said they would support Obama over McCain. She was seen by most as more honest than Obama and as the candidate who most shares voters' values.
Overall, Clinton dominated Obama across virtually all categories of voters, winning strongly among men, women and whites, as well as people of virtually all ages, income and education levels.
Obama won clearly only among blacks, taking nine in 10 of their votes. He and Clinton were running about even among independents - a group he has won in most states.
Those saying John Edwards' endorsement last week of Obama was important were split evenly between the two contenders, while those saying it was insignificant backed Clinton heavily.
The Kentucky data came from an exit poll by Edison Media Research and Mitofsky International for The Associated Press and television networks conducted in 30 precincts in the state. The preliminary data was based on 1,342 people voting in Kentucky's Democratic contest, with a margin of sampling error of plus or minus 5 percentage points.
The Oregon figures came from telephone interviews the companies conducted of 1,201 people voting in that state's contest, with a margin of sampling error of plus or minus 4 points. Oregon votes by mail ballot, and those interviews were conducted from May 12-18.
