In most cases, he followed the recommendation of the parole board, but in several cases he overrode the objections of prosecutors, judges and victims’ families. And in several, he followed recommendations for clemency from Baptist preachers who had been longtime supporters.

Prosecutors told him he was ignoring his responsibility to explain to citizens why he was setting free convicted murderers and rapists. His response, some of them say, was to blame others and strike out against his critics  an off-note from a man they consider a gifted politician.

Image Former Arkansas Gov. Mike Huckabee, right, at a rally in 2000. Credit... Danny Johnston/Associated Press

“Victims groups were pretty well ignored, along with boots-on-the-streets law enforcement and good citizens who sit on these juries,” said Larry Jegley, who objected to Mr. Clemmons’s clemency request as the prosecuting attorney for Pulaski County, where he was convicted.

Robert Herzfeld, then the prosecuting attorney of Saline County, wrote a letter to Governor Huckabee in January 2004, saying his policy on clemency was “fatally flawed” and suggesting that he should announce specific reasons for granting clemency. Mr. Huckabee’s chief aide on clemency wrote back: “The governor read your letter and laughed out loud. He wanted me to respond to you. I wish you success as you cut down on your caffeine consumption.”

“It was all a very personal issue for him,” said Mr. Herzfeld, who later sued successfully to overturn one of Mr. Huckabee’s clemency decisions, which would have set free a man convicted in a bludgeoning death. “It was always about how I was trying to get him or another prosecutor was trying to get him, not about how to do it right. He’s brilliant politically and very likable, but it seems like there’s a blind spot on this issue.”

With Mr. Clemmons, political consultants say Mr. Huckabee may have hit his Willie Horton moment

“As a front-runner, obviously with circumstances like this, it’s out there as a big issue,” said Ed Rollins, the manager of Mr. Huckabee’s 2008 presidential campaign.