The Missouri House is expected to consider a requirement for voters to show photo identification at the polls.
State lawmakers have debated the concept previously, but this is the first time Republicans have held a veto-proof majority in both the House and Senate.
In the past, discussion generally fell along party lines with Republicans favoring the idea and Democrats opposing it.
Supporters contend a photo ID requirement would help prevent election fraud. Critics say there have not been recent known instances of voter impersonation and that the measure could make voting harder for some Missourians.
House members were to consider both a constitutional amendment allowing for a photo ID requirement and separate legislation to implement it.