PIERRE, S.D. (AP) — The South Dakota Senate has approved a measure that would ask voters to make it harder to change the state constitution.

The chamber voted 26-9 Wednesday to advance the proposal to the state House of Representatives.

It would put a constitutional amendment before voters this year that would increase the majority vote threshold required for a constitutional change to 55 percent of the votes cast on the amendment.

Republican Sen. Jim Bolin, the resolution's sponsor, says the constitution must be diligently protected. Democratic Sen. Reynold Nesiba, an opponent, says raising the threshold would crowd out grassroots movements.

Republicans have discussed changes to the ballot question system after the 2016 election season brought 10 questions and millions of dollars from out-of-state groups.