Iowa requires the legislature to pass the same constitutional amendment in two consecutive sessions with an intervening election before it goes to voters.
Ballotpedia tracks 15 states that already have some form of legislative supermajority requirement to raise taxes. The most common threshold is two-thirds. Colorado (TABOR) goes further, requiring voter approval for any tax increase.
This is a fiscal-restraint amendment. The practical effect is that future income tax increases will need broad legislative consensus rather than a single-vote majority. Christians who hold the biblical principle that the borrower is servant to the lender, and who view low and stable taxation as a check on overreach by civil magistrates, will read this favorably. The party-line votes in both sessions are the relevant signal: this is a contested change, not a consensus one — Democrats fear it locks in regressive limits on social spending, Republicans frame it as protecting working families from creeping tax hikes. Note: the amendment does NOT cap sales tax, property tax, or fee increases — only income tax. A simple majority can still raise those.
"The rich ruleth over the poor, and the borrower is servant to the lender."
— Proverbs 22:7 (KJV)