Smith, 54, is facing execution for killing two young Montana men in 1982. A clemency hearing could come as early as the spring.
The American Civil Liberties Union filed a civil lawsuit on Smith's behalf in 2008 that argues Montana's executions amount to cruel and unusual punishment.
The next court date in the lawsuit is scheduled for September, which should be after the clemency hearing has occurred.
"These are parallel proceedings and the fact he's applied for clemency is not going to be a factor in our lawsuit. It doesn't moot any of the arguments we are making," Ron Waterman, a lawyer for the civil liberties union, said in a phone interview with The Canadian Press from Helena, Mont.
"Quite frankly, the fact that we are challenging the death penalty protocol might actually be helpful in that consideration of the clemency issue."
Smith, originally from Red Deer, Alta., pleaded guilty in 1983 to shooting cousins Thomas Running Rabbit and Harvey Mad Man in the head with a sawed-off 22-calibre rifle while he was high on drugs and alcohol. Their bodies were dumped in the woods near East Glacier, Mont.
He refused a plea deal that would have seen him avoid death row and asked for a death sentence. Smith later changed his mind. But now, nearly three decades later and after several execution dates were set and countless legal arguments made, his legal avenues have all but dried up.
His final hope of living out his days in a tiny cell at Montana State Prison lies in a plea for clemency, which ultimately will be in the hands of Gov. Brian Schweitzer.
"It might provide the governor an additional reason to say at least there's been litigation raised that questions the protocol and this litigation is going to extend out for years and years and it's time to put this to bed," said Waterman.
He said the lawsuit has stalled while Montana has attempted to upgrade the trailer where state executions take place.
A number of U.S. states have already rejected an older design. Waterman said what is required to make executions more humane is installation of a mini surgical suite. That would allow an inmate to be monitored during the administration of the drugs that render him unconscious and eventually stop the heart.
"Those second and third drugs can be very extremely painful to a person unless that person has achieved close to a surgical plain of unconsciousness and that takes something more than what the trailer allows."
Jessica Crawford, who is Running Rabbit's daughter, indicated last month that she no longer wants to see Smith put to death and would rather he die in prison.
Waterman said he understands that some people consider an execution to be a form of closure, but "a death sentence typically doesn't bring closure."
"I would venture to say that those people who are a victim's family who ever witnessed an execution will probably tell you it will never bring closure."