One way to gauge public perception of capital punishment in the United States is to study the official platforms of the Democratic and Republican parties. These documents are released a few months before each presidential election in order to clarify each party’s current stances on complex political issues. Political science research has demonstrated that “Congress voted in line with their platforms more than 80 percent of the time,” and as such the platforms “help political scientists understand how parties change” as years pass.

Examining the platforms since 1960, it becomes clear that capital punishment did not become a major aspect of public debate until 1972, the same year the U.S. Supreme Court temporarily abolished the death penalty with its decision in Furman v. Georgia. The Democrats called for permanent abolition of the death penalty, whereas the Republicans still did not make an express policy statement on it one way or the other.

The 1976 Republican Party Platform claimed that capital punishment is a state-by-state issue. In 1980, the Republican Party revised their stance, stating that “We believe that the death penalty serves as an effective deterrent to capital crime and should be applied by the federal government and by states which approve it as an appropriate penalty for certain major crimes.” The platform in 1984 tempered that message by saying capital punishment should be employed only “where appropriate” and “carried out humanely.”

But in 1988, the Republican Party vowed to “reestablish the federal death penalty” and truncate the federal habeas corpus appeals process, so condemned inmates would be executed within a shorter timeframe. In 1992, the party platform demanded the death penalty for serious drug trafficking offenses. The Republican platform of 1996 advocated for expanding the field of death-eligible offenses to rape, and advocated for pro-death penalty judicial appointments. By 1996, Democrats also approved of limiting the appellate process, which President Bill Clinton did by signing the Antiterrorism and Effective Death Penalty Act of 1996.

The year 2008 saw tonal and doctrinal changes in both parties’ platforms. The Democratic Platform stated in 2008 and 2012 that the death penalty must “not be arbitrary,” whereas the 2008 Republican Platform criticized judges allowing defendants guilty of “heinous crimes” to avoid the death penalty on alleged technicalities.

This year is the first time since 1972 that the Democratic Platform deemed the death penalty “a cruel and unusual form of punishment which has no place” in the nation. The 2016 Republican Party Platform also takes a slightly more restrained approach than previous years, stating that “the constitutionality of the death penalty is firmly settled by its explicit mention in the Fifth Amendment” and that states’ rights in this arena should not be abridged. Interestingly, this stance is most similar to the party’s 1976 position, when the death penalty was reinstated (albeit with constraints) by Gregg v. Georgia.

Public support of the death penalty is hovering at a 40 year low according to the most recent Gallup poll, and 56% of Democrats now oppose the punishment. A number of polls show a growing preference for life without parole over the death penalty, which may explain the recent trends in both party’s platforms.