State legislatures are the primary policymaking bodies in the states. With nearly 7,400 lawmakers serving across 99 chambers, they pass the vast majority of laws that affect Americans' daily lives, from taxes and education to criminal justice and healthcare. In a country where federal legislation often stalls, state legislatures have become the true engines of policy change.
How State Legislatures Work
Every state except Nebraska uses a bicameral legislature: two separate chambers that must both pass a bill before it can reach the governor's desk. State senates are the upper chamber, typically smaller and with longer terms. The lower chamber goes by different names: the House of Representatives in most states, the Assembly in California, Nevada, New York, New Jersey, and Wisconsin, and the House of Delegates in Maryland, Virginia, and West Virginia.
Nebraska is the lone exception, and its path to a single-chamber legislature is one of the stranger stories in American political history.
How Nebraska Became the Only Unicameral Legislature
Nebraska began with a standard two-chamber legislature. The push to abolish one chamber came from U.S. Senator George Norris, who after decades in Congress had grown deeply disillusioned with partisan politics, particularly the secrecy of conference committees where the two chambers reconciled legislation behind closed doors. Norris later wrote that he had come to see both parties as "machine-controlled" and laid out his plan for "A Model State Legislature" in an influential New York Times essay: small, nonpartisan, and unicameral.
Earlier attempts to amend Nebraska's constitution failed in 1919 and 1923. The 1934 effort succeeded for several reasons: organizers paid signature gatherers five cents per name, generating 150 percent of the required signatures; widespread dissatisfaction with the legislature during the Great Depression made voters receptive; and the initiative shared the ballot with two popular measures (repealing Prohibition and legalizing pari-mutuel gambling) that drove turnout among voters who might not otherwise have participated. All three measures passed overwhelmingly.
Today, the Nebraska Legislature has 49 members serving four-year terms. Officially nonpartisan (no party labels appear on the ballot), the chamber has developed many of the same dynamics as a traditional legislature. Senators increasingly caucus along partisan lines, and partisan filibuster fights have become a regular feature of its sessions.
Benjamin Franklin likened a bicameral legislature to "putting one horse before a cart and another behind it, both pulling in opposite directions." George Washington saw it differently. When Thomas Jefferson asked why the Senate existed, Washington reportedly replied that the framers had created it to "cool" legislation from the House, just as a saucer was used to cool hot tea. That tension between rapid democratic action and deliberate restraint is still built into every state legislature that uses two chambers.
Before the U.S. Supreme Court's landmark Reynolds v. Sims decision in 1964, state legislative districts were wildly unequal. In one extreme case, a California state senator represented millions of residents while a senator from a rural district represented fewer than a thousand constituents. The Court's ruling that all districts must be roughly equal in population fundamentally reshaped American democracy at the state level.
"Legislators represent people, not trees or acres. Legislators are elected by voters, not farms or cities or economic interests."
Legislatures also vary dramatically in how they operate. California and New York are essentially full-time bodies that meet year-round. Montana, Nevada, North Dakota, and Texas still hold biennial sessions, meeting only every other year, though the demands of modern governance have put pressure on each of them to shift to annual sessions.
What is "sine die"? Latin for "without day," this term refers to the final adjournment of a legislative session with no set date for reconvening. When a legislature adjourns sine die, any bills that didn't pass are dead and must be reintroduced in the next session. Governors can still call special sessions for specific purposes.
Chamber Sizes and Structure
The New Hampshire House of Representatives, with 400 members, is the fourth-largest English-speaking legislative body in the world, behind only the U.S. House, the British Parliament, and the Indian Lok Sabha. At the other extreme, the Alaska Senate has just 20 members. Across all 50 states, there are approximately 7,386 total legislative seats distributed among 99 chambers (Nebraska's unicameral legislature is counted as a single chamber).
Most state senators serve four-year terms, often staggered so that only half the chamber is up for election in any given cycle. Lower chamber members typically serve two-year terms, meaning every seat is on the ballot every election.
| State | Chamber | Seats | Notes |
|---|---|---|---|
| New Hampshire | House | 400 | 4th-largest English-speaking legislative body |
| Pennsylvania | House | 203 | |
| Georgia | House | 180 | |
| Texas | House | 150 | |
| Nebraska | Legislature | 49 | Unicameral; officially nonpartisan |
| Wyoming | Senate | 30 | |
| Delaware | Senate | 21 | |
| Nevada | Senate | 21 | |
| Alaska | Senate | 20 | Smallest state senate |
The Republican Wave
The story of state legislative politics over the past four decades is, in large part, the story of Republican ascendancy. In 1982, Democrats controlled 34 state legislatures, their modern peak. Republicans held just 11. The purple middle, states with split legislative control, was a broad and comfortable norm.
The 1994 Republican Revolution marked the turning point. Republicans roughly doubled their legislative control in a single cycle, going from controlling about 8 state legislatures to more than 18. But the true inflection came in 2010, when a midterm backlash against President Obama, the Tea Party movement, and, critically, the timing of the redistricting cycle combined to create a structural advantage Republicans have maintained ever since.
REDMAP: How 2010 Reshaped the Map for a Decade
In 2010, the Republican State Leadership Committee launched the Redistricting Majority Project (REDMAP), a strategy to target state legislative races in states that would redraw congressional and state legislative maps the following year. By investing in chambers in Ohio, Pennsylvania, Michigan, Wisconsin, and North Carolina, Republicans secured control of the state legislative redistricting process in states representing a large share of the country's population.
The result was a set of maps that locked in Republican advantages across state and congressional districts for the following decade. After the 2020 Census, Republicans controlled state legislative redistricting outright in 21 states, compared to 9 for Democrats. Independent or bipartisan commissions now handle the process in 14 states, a reform pushed in part by backlash to REDMAP-era gerrymandering. Whether Republicans can replicate that structural edge heading into 2030 depends heavily on who controls state legislatures after the 2028 and 2030 elections.
Republicans peaked at 32 controlled legislatures after the 2016 elections. Even after Democratic gains in 2018 and 2022, Republicans still control 57 of 99 chambers compared to Democrats' 39 (Nebraska's nonpartisan unicameral legislature accounts for the 99th). States with genuinely split legislative control (one chamber per party) keep shrinking. Today, only 2 states have split legislatures, down from more than a dozen just a decade ago.
Supermajorities: The Real Power
In state politics, the most important threshold isn't majority control; it's the supermajority needed to override a governor's veto. Most states require a two-thirds vote in each chamber, but seven states use a three-fifths threshold, and six states require only a simple majority to override. Alaska is unique in requiring a combined two-thirds vote from both chambers sitting in joint session.
Republicans currently hold veto-proof supermajorities in both chambers of 21 states. Democrats hold them in 9. In states like Kansas, Kentucky, North Carolina, and Vermont, these supermajorities effectively neutralize the opposing governor's veto power. For a comprehensive state-by-state breakdown of veto override thresholds and which parties currently hold them, see our Supermajorities page.
Excess seats: "Outperforming the baseline" means holding more legislative seats than the presidential vote share in those districts would predict. Republicans outperform that baseline in 39 of 99 chambers, while Democrats do so in only 13. The remaining 47 chambers are roughly proportional to presidential results. This structural advantage, driven by redistricting, geographic sorting, and recruitment patterns, means that even in a neutral national environment, Republicans start with a significant edge at the state legislative level.
The 2026 Landscape
The 2026 cycle will be the most consequential for state legislatures since 2022. Approximately 5,800 seats will be on the ballot, with competitive races in a handful of states that could reshape the partisan map.
The toss-up chambers to watch: Arizona (both chambers), Michigan (the House), Minnesota (the tied House), Wisconsin (both chambers, with new maps after the Wisconsin Supreme Court struck down the old ones), and New Hampshire (the 400-member House, where Republicans hold a slim majority). Pennsylvania's Senate, where Democrats need three pickups to break the Republican majority, and Maine's House, where Democrats hold a narrow edge, round out the competitive landscape.
In at least five states, legislative outcomes could determine whether one party achieves unified control of state government or whether an existing trifecta gets broken. The 2028 and 2030 legislative elections will ultimately determine which party controls the redistricting process after the next Census, but the organizational and structural advantages built in 2026 will shape both of those cycles.