The Wyoming state Senate late last week voted down a proposal to abolish the death penalty in the state.

State senators voted 12-to-18 against the abolition proposal, the Casper Star Tribune reported. This marked a reversal from its hearing in committee, when the bill received unanimous support from members of the Senate Judiciary Committee.

If passed, the bill would have replaced all sentences of death with a maximum sentence of life without the possibility of parole. This would have made Wyoming the 21st state to abolish the death penalty, according to the pro-abolition Death Penalty Information Center.

Abolition had previously passed the state House, on the back of a bipartisan coalition of anti-death-penalty Democrats and new pro-reform Republicans. The latter group, led by bill author Rep. Jared Olsen, made its argument based in large part on fiscal conservative grounds—thanks to never-ending procedural wrangling by defense attorneys, capital trials can cost states millions of dollars to prosecute.

The bill attracted the support of House Republican leadership, including House Speaker Steve Harshman, House Majority Leader Eric Barlow, and House Majority Whip Rep. Tyler Lindholm. It also was backed by the state's branch of the ACLU and the Roman Catholic dioceses of Cheyenne.

But this support was not enough to clinch victory in the more conservative Senate, even though some state senators voiced similar fiscal concerns.

Had it passed, abolition in Wyoming would have been largely a symbolic gesture. Mark Hopkinson, killer of four, remains the only individual to actually be executed in Wyoming since the Supreme Court reinstated capital punishment in 1976. The state's death row is completely empty. With just 15 murders in 2017, it is likely to remain so for the foreseeable future.

Because of its highly limited impact, the effort to abolish capital punishment in Wyoming can be understood as part of a larger effort by abolitionists to run up the number of states without the death penalty. Clinching a majority of states or more would allow abolitionists to argue that "evolving standards of decency"—which the Supreme Court has used to interpret the Eighth Amendment's prohibition on "cruel and unusual punishment" since 1957—have reached the point of excluding execution as an acceptable consequence for murder.

Despite Wyoming's rejection of abolition, there remain a number of states where the death penalty is up for debate. Opponents of capital punishment claimed a supermajority in the New Hampshire state Senate on election day, criminal justice news site The Appeal reported. The Senate had previously voted for abolition, but been vetoed by Gov. Chris Sununu (R.)—the new supermajority would allow an override of that veto.

In Washington state, meanwhile, the state Supreme Court ruled in October that death penalty in its current form violated the Washington constitution. Presidential contender Gov. Jay Inslee (D.) lauded the ruling, calling it a "a hugely important moment in our pursuit for equal and fair application of justice."

Notably, the Washington ruling applied only to capital punishment as currently constituted—voters or the legislature may move to fix it, just as Californians did in 2014.

Other red states are also weighing the possibility of abolition. Kentucky State House Whip Chad McCoy (R.) had introduced an abolition bill, telling the Hill, "when you talk about death penalty, a lot of people immediately want to have a criminal justice angle on it or a morality angle. And mine is purely economics."