If African-Americans died at equal rates as whites, some key close elections that Republicans won would have gone to Democrats instead, researchers concluded. And these electoral results have implications for the policies that affect the disproportionate death rate in the first place, they added.
Death rates for blacks have been 20 to 40 percent higher than whites for decades, according to the U.S. Centers for Disease Control and Prevention. Heart disease and cancer are the leading killers.
The biggest difference in mortality falls between the ages of 40 and 65 — years when voting activity also peaks.
Researchers wanted to know what impact that was having on African-American political influence.
"Who gets elected comes with a whole sense of what are the right policies ... and how best to serve any population," said study co-author Arline Geronimus at the University of Michigan Population Studies Center. If there were more black voters, she added, they could push harder for more policies to address health disparities.
Geronimus and colleagues started with CDC mortality data from 1970 to 2004. Because not everyone votes, they factored in voting habits for different races and age groups. And they calculated what party these hypothetical new citizens would have voted for based on exit polls.
Because blacks vote overwhelmingly Democratic, these hypothetical voters would have reversed the results of seven Senate and 11 gubernatorial elections that Republicans won by narrow margins during that 35-year period. Democrats would have controlled the Senate continuously from 1986 to 2002. Republicans controlled the chamber for eight of those years.
"The point is not so much the specific number of elections that would have gone one way or the other," she noted. "What it does tell you is that ... this health inequity does help silence black voices in the electorate."
The higher death rates among blacks, "among all the other reasons they are unjust and tragic, are a major threat to democracy," Geronimus said.
If death rates were equal, the authors speculate that more states would have agreed to expand the government-funded Medicaid health insurance program, which is part of President Barack Obama's signature health care law.
The law itself might have been closer to the European or Canadian government-run system than the free market system that the president signed, according to political science professor Michael Dawson, director of the University of Chicago Center for the Study of Race, Politics and Culture, who was not involved with the research.
"Black Democrats are considerably to the left of their white counterparts," Dawson said. And that would have implications beyond health care.
"They're much more for a strong central state, much more for economic redistributions through the tax system, much more for a strong safety net," he added. "It would be a country that would be more center-left than center-right."