An execution table in Baltimore in 2004. (Steve Ruark/Associated Press)

Support for the death penalty is at a four-decade low among the American public, but that may be of little consequence in the struggle over the future of capital punishment. That’s because the death penalty is the practice not of the nation, but rather of a handful of states.

The federal government is a minor player in criminal justice, housing just 1 in 8 inmates. The federal government executed two prisoners on the same day in 1957, but implemented capital punishment only four times in the 60 years since. It’s states that charge and sentence almost all the individuals who commit the crimes that lead to capital sentences (e.g., murder). And, more specifically, it’s just five of those states that are the true force behind capital punishment, accounting for 90 percent of the 122 executions carried out in the past three years.

Source: Bureau of Justice Statistics

Texas stands out for its particularly outsized role, accounting for over a third of capital punishment. Florida, Georgia and Missouri each account for about 1 in 7 executions, and Oklahoma accounts for about 1 in 12. The other 45 states collectively account for only 10 percent of prisoner executions, even though the law in 30 of those states allows capital punishment.

Rather than ask “why does the United States have capital punishment,” it makes more sense to ask why these particular five states apply it so often. Obviously, all are politically conservative states within or bordering the South. But this is also true of Louisiana, Mississippi, South Carolina, North Carolina and Tennessee, none of which has put a prisoner to death in recent years (indeed, Louisiana came close to abolishing the death penalty in this year’s legislative cycle.)

Stanford Law School Professor Robert Weisberg points to state-specific processes and incentives as drivers of the death penalty in a subset of conservative states. Most notably, he says, “Texas has elected judges. It is also located in the prosecutor-friendly 5th Circuit Federal Court of Appeals. Although the Supreme Court occasionally slaps down the Texas Court of Criminal Appeals and its federal accomplice, the Fifth Circuit, for allowing egregiously unfair capital trials, on the whole those lower courts have been happy to give Texas prosecutors a generously wide berth.”

Most states have abandoned the death penalty de jure or de facto. But in the absence of change in the handful of states that combine punitive views on crime with legal processes that facilitate capital punishment, the practice will remain a part of the criminal justice system.