Now, a big death penalty surprise in the wake of so much news about crime and punishment in America, the Nebraska legislature has just voted to ban capital punishment, the first solidly red state to do so in decades. Here's ABC's Pierre Thomas. Reporter: This week's vote in Nebraska has capped off a dramatic debate. For some crimes, death is the only appropriate punishment. No individual has the right to take the life of another, nor should the state. Reporter: Now, Nebraska could become the first conservative-leaning state to ban the death penalty, a move backed by many republicans who says it's a moral issue. My main objections come from my pro-life values. Reporter: But the republican governor, a death penalty supporter, has promised to veto the measure. Still the state legislature may have the votes to override him. The latest in significant challenges to capital punishment. Illinois enacted a decade moratorium. The state abolished the death penalty in 2011. In Oklahoma, the botched execution of 38-year-old Clayton Lockett last year, drew new scrutiny over the deadly multidrug cocktails used in the lethal injections. The U.S. Supreme court will soon to decide if that drug cocktail is cruel and unusual punishment. Nationwide, 18 states and D.C. Ban capital punishment. And now, a majority of Americans would favor life in prison over the death penalty. But for some victims and their families, the most heinous crimes deserve the ultimate punishment. This month, the federal jury sentenced tsarnaev to death. I wanted justice for my family. The ultimate justice was the death penalty. Reporter: But yet some in Boston had lobbied for life in prison. Capital punishment a particularizing issue. Exactly what they're seeing in Nebraska's difficult debate. For "This week," Pierre Thomas, ABC news, Washington. Nebraska republican state senator Colby cash joins me now, he voted in favor of abolishing the death penalty. Senator cash, you're a conservative republican, why did you vote to get rid of the death penalty? Well, for me, Jon, this was a practical thing. In Nebraska, we haven't executed anybody in 20 years. And it's been a cost to our state with lengthy appeals. But at the end of the day, we decided a penalty that we can't impose is a penalty that we shouldn't have on the books. If there was any other program that's costly as this has been we as conservatives would have gotten rid long ago. It wasn't so much the moral component of the state taking somebody's life, this was a practical -- Certainly. Well, certainly, some of my colleagues have come to this from a moral standpoint. I'm pro-life, and for some of us, in addition to the extreme costs and the inefficiency, supporting the death penalty just didn't seem to go with our pro-life values. Some of my colleagues came to it from that perspective as well. So, what's going to happen now? The governor said he would veto this law, will you be able to override his veto? Well, we'll see this week, but I believe there are the votes to override the veto, I do. Let me ask you, we saw a dramatic case of course in Boston, with the Boston marathon bomber sentenced to death in liberal Massachusetts, what do you say to victims' families who say that some crimes are so heinous they're simply must be the ultimate punishment? Well, I have talked to a lot of victims right here in our state and certainly there are victims on both sides of this issue, but in Nebraska, the victims' families that I have talked to have said, when a judge puts a sentence on somebody and says to that victim's family we're going to execute the perpator of the crime against your family the victims look at me and say, senator, how is that fair? When you can't do when you said you could do. So, I mean, there are two sides to the victim's stories. I don't speak for all of the victims. But there are two sides to that. All right, senator, cash, thank you for coming on this Sunday. Have a good memorial day. Back to the roundtable, S.E., what's your sense? Has the tide shifted on the death penalty? Yeah, my position as a conservative has long been against the death penalty, I don't find it to be moral or just. There are wrongful convictions that we hear about all the time, it's costly. It's bankrupted entire counties. For me, I have been trying to convince fellow conservatives to have a change of heart on this issue. But you're starting to see it shift now and you brought up the Boston bombing. Victims of that horrific event many of them came out publically and said they wanted life. Donna -- I totally agree with all of the things that S.E. Just said. Ernie chambers, the democrat, he's been an iconic leader in the state of Nebraska, being one of the first lawmakers in the country to put out a ban on South Africa years and years ago, this has been his cause for years and years. He said it was morally wrong. Finally, he's gotten his fellow conservative colleagues to join him. I applaud Nebraska for doing this. I'm a defender of the death penalty. It's both just and an important symbol for really heinous crimes. But I respect pro-life conservatives whose pro-life principles lead them to draw the line further. I'm curious what Hillary Clinton's position is. Her husband executed people as governor of Arkansas. Hopefully, we'll get a chance -- If she ever appears before the press -- Every republican candidate will give an answer on this. We are out of time. Thank you, everyone. Let's take a break.