Former secretary of state Hillary Clinton speaks to a cheering crowd of supporters in West Palm Beach, Fla., March 15. (Melina Mara/The Washington Post)

At first glance, the results from last week’s Democratic presidential primary in Pennsylvania appear to be strikingly similar to the last time Hillary Clinton ran for president. Nearly the same percentage of Pennsylvania primary voters supported her in both 2008 and 2016: 54.6 percent and 55.6 percent, respectively.

But while her aggregate vote tallies may have been comparable, Clinton’s coalition in Pennsylvania was much different than the last time she ran. In 2008, she won 63 percent of the white vote and only 10 percent of the black vote in Pennsylvania. Last week, she won just 51 percent of the white vote and a whopping 70 percent of the African-American vote in the state.

Those results, whereby Clinton’s white support declined by double digits while her black support skyrocketed, are similar to the results from other states. In Tuesday night’s Indiana primary, Hillary did 65 percentage points better with black voters than she did in 2008, but 17 points worse with whites.

The graph below shows that Clinton’s average share of the white vote in 2016 has been 10 points lower than it was against Barack Obama in the states that conducted exit polls in both election years. Meanwhile, her support among blacks is 60 points higher.

Graph by Michael Tesler. Graph reports Clinton’s average share of the top two-candidate vote across the states. Source: Exit Polls.

The dramatic turnaround in Clinton’s black support has already been discussed by a number of commentators. Little has been written, however, about the significant drop-off in Clinton’s white support from 2008 to 2016.

Clinton’s weaker support among whites in 2016 was anticipated by prior social science research, which showed that racial attitudes were perhaps the strongest predictor of white Americans’ preferences in the 2008 contest between Clinton and Obama. The effect of racial attitudes in the 2008 Democratic primaries completely reversed the long-standing pattern of racially liberal Democrats evaluating Clinton more favorably than racially conservative Democrats.

After Clinton joined the Obama administration, the original pattern reemerged, and Clinton once again became significantly more popular with white racial liberals than with racial conservatives.

It makes sense, then, that racial attitudes have had a much different effect on white Americans’ voter preferences in the 2016 Democratic primary than they had back in 2008.

Graph by Michael Tesler. Source 2008 ANES; 2016 ANES Pilot (Democrats and Democratic Leaners)

The graph above shows that the same attitudes about African Americans that had such a strong impact in 2008 were not powerful predictors of vote preference for Clinton in the American National Election Study’s 2016 pilot survey. Consequently, Clinton’s vote share has declined substantially from 2008 to 2016 among whites who rate blacks unfavorably and who express racially resentful sentiments such as blaming racial inequality on perceived cultural deficiencies in African American communities.

The same patterns can be found in other surveys. A poll conducted last week by YouGov for the Economist revealed that support for the Black Lives Matter Movement had no impact on white Democrats’ preferences for Clinton or Bernie Sanders. And my analyses of RAND’s Presidential Election Panel Survey (PEPS) shows that racial and ethnocentric attitudes have had little influence on the Democratic race in 2016.

We can also leverage the fact that some PEPS respondents were previously surveyed eight years ago. Again, racial attitudes had a notably different effect on the exact same individuals’ vote preferences in 2008 and 2016. In fact, no other factor predicts changes in Clinton support among these white panelists nearly as well as racial attitudes.

Graph by Michael Tesler. Source: RAND American Life Panel/Presidential Election Panel Survey. Numbers at the bottom represent the amount of respondents in each cell.

Clinton’s geographic coalition has changed, too — especially in Deep South states that have large numbers of African Americans and racially prejudiced whites.

Indeed, the final graph below shows strong negative relationships between Clinton’s county-level vote share in 2008 and her 2016 vote tallies by county in the Deep South states of Louisiana, Mississippi, Alabama and GeorgiaClinton did worst this year in the Deep South counties where she did best in 2008, and she performed best in heavily black counties where she lost overwhelmingly to Obama eight years earlier.    

Graph by Michael Tesler. Source: Dave Leip Election Atlas.

Racial attitudes and race have had a very different impact on Clinton’s two presidential bids. Without Obama on the ballot in 2016, Clinton’s support has increased significantly among blacks and racially liberal whites.

Despite her loss Tuesday night in Indiana, that improved standing among racial liberals has enabled her to withstand a sizable decline among racially conservative white voters and put her on track to winning the Democratic nomination.

Michael Tesler is assistant professor of political science at the University of California in Irvine and author of “Post-Racial or Most-Racial? Race and Politics in the Obama Era.