In state politics, the most important threshold isn’t majority control — it’s the supermajority needed to override a governor’s veto. When a party holds enough seats to override vetoes in both chambers, the governor’s leverage effectively disappears. Understanding these thresholds — and which parties currently meet them — is essential to understanding who actually governs in each state.
What Is a Supermajority?
A supermajority is any voting threshold that exceeds a simple majority (50% + 1). In the context of state legislatures, supermajorities come into play for several critical actions:
- Veto overrides — the votes needed to enact legislation over the governor’s objection
- Tax and revenue increases — some states require supermajorities to raise taxes
- Constitutional amendments — placing amendments on the ballot for voter approval
- Budget and appropriations — passing the state budget in certain states or circumstances
- Filibuster and cloture — Nebraska’s unicameral legislature requires a supermajority to end debate
- Emergency clauses — adding an emergency effective date to legislation
The veto override is by far the most consequential. When a party holds a veto-proof supermajority in both chambers, it can govern almost unilaterally — even if the governor belongs to the opposing party.
Veto Override Thresholds
Most governors veto legislation passed by the legislature. This gives the executive branch an important check on the legislative branch. However, every state legislature has the power to override a gubernatorial veto if lawmakers can muster a supermajority of votes to do so. The threshold for a veto override is not uniform by state, but the landscape breaks down into three tiers:
Two-Thirds (2/3) — The Standard
The majority of states use a two-thirds threshold, which is the hardest supermajority to achieve. In a 100-seat chamber, this means 67 votes. Some states measure this as two-thirds of elected members (the full chamber), while others measure two-thirds of members present and voting — an important distinction that can affect the effective threshold when members are absent.
Three-Fifths (3/5) — The Middle Ground
Several states require a slightly less “super” majority of three-fifths (60%), which is meaningfully lower than two-thirds. In a 100-seat chamber, this drops from 67 to 60 seats needed. States using the 3/5 threshold include:
Simple Majority — The Lowest Bar
A handful of states require only a simple majority to override a governor’s veto — the same threshold needed to pass the bill in the first place. In these states, the governor’s veto is largely symbolic: if the legislature had the votes to pass the bill, it almost certainly has the votes to override. States with majority overrides include:
Special Cases
- Alaska requires a two-thirds vote of both chambers sitting in joint session — a unique process where the 60 House members and 20 Senate members vote together, requiring 54 of 60 total votes.
- North Carolina did not grant its governor veto power until 1996, making it the last state to do so. Overrides require a three-fifths vote.
Beyond the Veto: Other Supermajority Requirements
Tax and Revenue Supermajorities
Some states have enshrined supermajority requirements for raising taxes or increasing revenue, making it structurally harder for legislatures to increase the tax burden regardless of which party is in power. These provisions are often the result of ballot initiatives or constitutional amendments driven by anti-tax movements.
Kentucky’s odd-year twist: Kentucky requires a three-fifths supermajority for raising revenue or appropriating funds only in odd-numbered years. In even-numbered legislative session years, a simple majority suffices for revenue and appropriations bills — creating a unique dynamic where the budget calendar affects the balance of power.
Constitutional Amendment Thresholds
Every state has a process for amending its constitution, and most require legislative supermajorities as part of that process. The most common patterns are:
- Two-thirds in one session — a single supermajority vote places the amendment on the ballot
- Three-fifths in one session — a lower bar, used in some states
- Simple majority in two successive sessions — a lower per-session threshold but requires passage in two different legislatures, adding a time delay
- Two-thirds in two successive sessions — the highest bar, requiring supermajorities twice
Nebraska’s Filibuster
Nebraska’s unicameral, officially nonpartisan legislature has its own supermajority dynamic: 33 of 49 senators (a two-thirds supermajority) are required to invoke cloture and end a filibuster. This means a minority of just 17 senators can block legislation indefinitely, giving the minority caucus outsized influence even in a chamber where one party nominally controls a majority of seats. In 2024, Republicans gained the numbers to block filibusters after a party-switching member came over to their side — and Democrats made breaking that supermajority a top priority in the November elections.
The Electoral Battlefield
Every election cycle, breaking up vulnerable supermajorities is a key political objective for the party out of power. While the headlines focus on parties that manage to flip a legislative chamber, political operatives are also quietly targeting states where a handful of seat flips could strip the opposing party of its veto-override power.
In 2024, Democrats succeeded in breaking the Republican supermajority in the North Carolina House — a huge win for incoming Governor Josh Stein (D). But they fell short in Kansas, where Republicans actually expanded their narrow supermajorities in both chambers. And in Vermont, Republicans flipped 24 seats in the 150-member House, breaking up the Democratic supermajority and restoring Governor Phil Scott’s (R) veto power after years of being overridden.
Raw seat totals can be deceptive. In 2024, Republicans picked up 24 seats in New Hampshire’s 424-seat legislature and 24 seats in Vermont’s 180-seat House. But the Vermont gains were far more consequential: they broke the Democratic supermajority and fundamentally shifted the balance of power in the state.
Party switching can also reshape the supermajority map. When a North Carolina Democrat switched to the Republican Party in 2023, it gave the GOP a veto-proof supermajority in the state House — a single defection that transformed the governor’s ability to block legislation.
Effective Veto-Proof States
The most politically significant scenario is when a party holds a veto-proof supermajority in both chambers while the governor belongs to the opposing party. In these states, the governor’s party affiliation is almost irrelevant to legislative outcomes — the majority party can pass its agenda over any veto.
When you factor in supermajorities, the picture of truly divided government in America is even bleaker than it appears. Although roughly 10–12 states have nominally divided government, the number where both parties genuinely share governing power may be as low as six.
And on paper, some states look divided even when they’re not. Vermont’s popular Republican governor faces a Democratic legislature that, until recently, could override his vetoes at will. In Connecticut, a dozen Progressive and independent legislators work with Democrats to effectively govern as a supermajority capable of overriding vetoes from the governor. The formal partisan labels don’t always tell the full story.
50-State Reference
The table below shows veto override thresholds and current supermajority status for every state legislative chamber. Click column headers to sort.