Iowa’s legislature will probably pass HF 399, which permits people to register at the polls on election day. Iowa’s neighbors Minnesota and Wisconsin have had same-day voter registration for many years, and the perception is that it works well there. Iowa Democrats are supportive of the idea, and hold a majority in both houses of the legislature, and the governorship.
This proposal must apply to the general election only. Iowa already lets voters change their party registration on primary day and vote in the primary of their new party– hence, open primaries.