A Republican-backed proposal to make it harder to amend Missouri's constitution got initial approval from the state House on Wednesday, moving a top GOP priority closer to becoming law.

Lawmakers voted 106-50 along party lines in favor of the proposed constitutional amendment.

Republican lawmakers have been trying for years to crack down on initiative petitions, which have been used to enact policies that the Republican-led Legislature either avoided dealing with or opposed. For example, a 2020 citizen-led ballot initiative forced the state to expand Medicaid coverage, despite years of resistance from Republicans. Voters then legalized adult recreational use of marijuana in 2022, a long-avoided topic in the Legislature.

The measure needs a second vote of approval in the House to move to the GOP-led Senate, where top Republicans have voiced support for a higher threshold to change the constitution. The second House vote is scheduled for Thursday.

The House proposal would raise the bar for amending the constitution from a simple majority vote to at least 60%. If passed by lawmakers, the amendment would need voter approval.

Republicans in the House argued it's currently too easy to amend the state constitution.

“I believe that the Missouri Constitution is a living document, not an ever-expanding document,” Republican sponsor Rep. Mike Henderson told colleagues during floor debate. “And right now it has become an ever-expanding document.”

House lawmakers voted down a Democratic amendment that would have applied the same 60% threshold to pass the amendment itself.

“The simple fact is: If we think this should be the case, let’s make it the case on this,” Democratic Rep. Peter Merideth said.

The amendment notably would not increase the number of voter signatures needed to put an amendment on the ballot, as some lawmakers initially wanted.

Republican Senate President Pro Tem Caleb Rowden has said he would be hesitant to make it more difficult to put ballot proposals before voters and instead favors making it harder to pass constitutional changes.

The House measure also would require public forums in all eight of Missouri's congressional districts, an attempt by proponents to help raise awareness about suggested constitutional changes.

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