From [HERE] Fewer than half of Americans now believe the death penalty is fairly applied in the United States, according to the 2018 annual Gallup crime poll of U.S. adults, conducted October 1-10. The 49% of Americans who said they believed the death penalty was "applied fairly" was the lowest Gallup has ever recorded since it first included the question in its crime poll in 2000. The percentage of U.S. adults who said they believe the death penalty is unfairly applied rose to 45%, the highest since Gallup began asking the question, and the four-percentage-point difference between the two responses was the smallest in the history of Gallup's polling.
The poll also found that, even as the number of new death sentences are near historic lows, the percentage of Americans saying that the death penalty is imposed too often continued to rise and the percentage saying it is not imposed enough continued to decline. 57% of U.S. adults said the death penalty was imposed either "too often" (29%) or "about the right amount" (28%). In 2010, just 18% said the death penalty was imposed too often. While a plurality of 37% said the death penalty was not imposed enough, that figure was down 16% from the 53% level who in 2005 said it was not imposed enough. Gallup analyst Justin McCarthy wrote that "as executions in the U.S. have decreased along with the generally sinking crime rate, Americans have become more likely to say capital punishment is unfairly applied and that it is imposed too frequently."
Gallup measured overall support for capital punishment at 56%, which McCarthy described as "similar to last year's 55%." 2017, he said, "marked the lowest level of support for the practice since 1972." He said "support for capital punishment ... has been trending downward since peaking at 80% in the mid-1990s during a high point in the violent crime rate." The poll measured opposition to the death penalty at 41%, the same as last year's 45-year high. A national Pew Reseach Center poll released in June 2018 reported support for the death penalty at 54% and opposition at 39%. A 2017 study reported that murders in the 37 states that authorized the death penalty in 1994 declined by 35.4% between then and 2014, but that death sentences declined by 76.5%—more than double that rate—over the same time frame.