That compares with 46 percent of whites who feel the system is neutral racially.
Nearly two-thirds of Republicans believe that the recent high-profile killings of black men by police are isolated incidents, compared with 6-in-10 Democrats who are concerned those killed represent a broader trend.
The nationwide poll was conducted last week, days after riots erupted in Baltimore following the death of Freddie Gray. Gray suffered a fatal spinal injury while in police custody.
"Democrats and Republicans understand the deaths of Michael Brown, Eric Garner, and Freddie Gray in dramatically different ways," Daniel Cox, research director at the Public Religion Research Institute said in a statement.
"Where Democrats see a pattern, Republicans see a series of isolated incidents," he said. "These deep partisan divisions will almost certainly be reflected in the way each party assesses issues within the criminal justice system."
The survey also found disparities in how members of various religions view the criminal justice system. Close to six in ten white evangelical Protestants say that recent killings of black men are isolated incidents, a view shared by fewer white mainline Protestants (47 percent) and white Catholics (50 percent).
More than 6-in-10 religiously unaffiliated Americans and 7-in-10 minority Protestants say that such killings by police are part of a broader pattern, according to the group.
The poll found that more than two-third of Americans had "heard a lot" about the protest demonstrations and riots in Baltimore compared with 24 percent who said they had heard a little and six percent who were unaware of last week's unrest.