Deep Research: Supermajority laws around the states

Here are the results of my first use of OpenAI’s Deep Research tool. I asked for information that I know well – and in which inaccurate research has been published. It did a great job and relied substantially on my own research. But it also went beyond my list – identifying protest petition statutes in two states I had missed: New Mexico and South Dakota. That’s embarrassing. Deep Research also turned up an important, related law I hadn’t known: Downzonings in Wisconsin require a 2/3 majority vote. Getting the prompt right First, I asked ChatGPT 4o how to write the prompt. I’m a land use, housing, and zoning researcher. A key question in my area is how easy or difficult it is to change zoning. In most states, to change the zoning of a particular parcel or the text of a particular zoning district requires a simple majority vote of the city council, town meeting, or other legislative body. I’d like to ask Deep Research to find out which states, if any and under which conditions, require a supermajority vote to change zoning. Can you help me write a prompt to pose this question to Deep Research? GPT replied: Here’s a clear and precise prompt for Deep Research:_______________________________________________________________________Research Request: Supermajority Requirements for Zoning Changes by State I’m conducting research on the legal and procedural requirements for zoning changes in different U.S. states. In most states, changing the zoning of a specific parcel or amending the text of a zoning district requires a simple majority vote by the relevant legislative body (e.g., city council, town meeting). However, I am interested in identifying states where a supermajority vote is required under certain conditions. Please provide: 1. A list of states that require a supermajority vote for zoning changes.2. The specific conditions under […]

Here are the results of my first use of OpenAI’s Deep Research tool. I asked for information that I know well – and in which inaccurate research has been published. It did a great job and relied substantially on my own research. But it also went beyond my list – identifying protest petition statutes in two states I had missed: New Mexico and South Dakota. That’s embarrassing.

Deep Research also turned up an important, related law I hadn’t known: Downzonings in Wisconsin require a 2/3 majority vote.

Getting the prompt right

First, I asked ChatGPT 4o how to write the prompt.

I’m a land use, housing, and zoning researcher. A key question in my area is how easy or difficult it is to change zoning. In most states, to change the zoning of a particular parcel or the text of a particular zoning district requires a simple majority vote of the city council, town meeting, or other legislative body. I’d like to ask Deep Research to find out which states, if any and under which conditions, require a supermajority vote to change zoning. Can you help me write a prompt to pose this question to Deep Research?

GPT replied:

Here’s a clear and precise prompt for Deep Research:
_______________________________________________________________________
Research Request: Supermajority Requirements for Zoning Changes by State
I’m conducting research on the legal and procedural requirements for zoning changes in different U.S. states. In most states, changing the zoning of a specific parcel or amending the text of a zoning district requires a simple majority vote by the relevant legislative body (e.g., city council, town meeting). However, I am interested in identifying states where a supermajority vote is required under certain conditions.
Please provide:

1. A list of states that require a supermajority vote for zoning changes.
2. The specific conditions under which a supermajority is required (e.g., protests from property owners, changes inconsistent with a comprehensive plan, state-imposed rules).
3. Citations to legal sources (state statutes, case law, municipal codes) supporting these requirements.
4. Any relevant exceptions or nuances, such as different rules for different types of zoning changes (rezoning vs. text amendments).

The research should focus on statutory or widely applied legal requirements rather than isolated municipal rules unless they reflect a statewide policy trend.
_______________________________________________________________________


This should help you get a thorough and well-documented response. Would you like any refinements?


Deep Research clarifies the request

I used that prompt in Deep Research. It asked for clarification before going further:

Your research request is well-structured and clear. To ensure the most comprehensive and useful results, could you clarify:

1. Time Sensitivity: Do you need the most up-to-date legal information as of 2024, or would older sources also be useful?
2 Focus on Specific Government Levels: Are you only interested in state-imposed supermajority requirements, or should we also consider widely adopted municipal policies that indicate a broader trend?
3. Scope of Legal Sources: Should the research include only statutory law and case law, or would administrative rulings and legal interpretations (e.g., attorney general opinions) also be helpful?

Once confirmed, I will begin the research and provide a detailed response.

I replied:

Thanks.

1. Older sources would be more useful, but please confirm if policies have changed since those sources.

2. I’m interested in state-imposed supermajority requirements.

3. Statutes, case law, administrative rulings, and legal interpretations are all helpful.

Deep Research’s output

After eight minutes, Deep Research provided the following, which I will include without indenting.

Supermajority Vote Requirements for Zoning Changes (By State)

Overview: Under many state zoning enabling laws, certain zoning changes (typically rezoning/map amendments) require more than a simple majority vote in the local governing body. The most common trigger is a valid protest petition filed by nearby property owners, which elevates the approval threshold to a supermajority (often two-thirds or three-fourths) (Rezoning Protest Petitions Are Ripe for Reform | Mercatus Center) (Memorandum). About 20–22 states have such protest?petition supermajority provisions in state law (Rezoning Protest Petitions Are Ripe for Reform | Mercatus Center) (Memorandum). A few states impose supermajority votes in other scenarios (e.g. general state mandates or special cases like downzoning). Below is a list of states with supermajority requirements, the conditions that trigger them, and key legal sources. We also note any major exceptions or recent changes (prioritizing older authority but noting updates).

Protest-Petition Supermajority Requirements

In these states, if a specified percentage of affected property owners formally protest a proposed zoning change, state law requires a supermajority vote of the city council or county board to adopt the change. Absent a valid protest, a simple majority suffices. The typical threshold is 20% of the owners of the land subject to the rezoning or of the immediately adjacent area, but a few states use different percentages (2005-006 | 2/24/2005 | Kansas Attorney General Opinion) (City of Springfield v. Goff, 918 S.W.2d 786 | Casetext Search + Citator). The required supermajority is usually either two-thirds (2/3) or three-fourths (3/4) of the governing body’s members, depending on the state (Memorandum) (Memorandum). (Notably, North Carolina and Wisconsin formerly had protest-petition supermajority rules but have repealed them in recent years (Rezoning Protest Petitions Are Ripe for Reform | Mercatus Center) (Zoning FAQ 5 | LWM, WI ).) Key state provisions include:

Note: In Ohio and West Virginia, state law provides an alternative mechanism: a qualified protest petition on a zoning amendment triggers a referendum of the voters rather than a supermajority council vote (Rezoning Protest Petitions Are Ripe for Reform | Mercatus Center). Likewise, Michigan’s county zoning law allows referenda on protested changes. These are exceptions to the supermajority approach.

Other Supermajority Requirements and Nuances

Summary: In sum, numerous states – including Texas, New York, Illinois, Arizona, Kansas, Iowa, Colorado, Connecticut, New Jersey, New Mexico, Delaware, Mississippi, Missouri, Montana, Nebraska, the Dakotas, Wyoming, and others – have laws empowering neighbors to force a higher voting threshold on rezonings (Rezoning Protest Petitions Are Ripe for Reform | Mercatus Center) (Memorandum). These laws generally require a two-thirds or three-fourths majority for approval when a defined percentage of nearby owners object in writing, with a few states charting their own course (Massachusetts’ across-the-board 2/3 requirement, Wisconsin’s downzoning rule, North Carolina’s repeal of protest petitions in 2015, etc. (Rezoning Protest Petitions Are Ripe for Reform | Mercatus Center) (Zoning FAQ 5 | LWM, WI )). The exact triggers and fractions vary by state, so the specific statutory language and any recent amendments or case law should be reviewed in each jurisdiction. The citations above to state codes and cases provide the legal basis for these supermajority zoning requirements.


¹ South Dakota’s statute uses 40%; see S.D. Codified Laws § 11-4-5 (municipal protest petitions) and § 11-2-19 (for county zoning, 20% triggers 2/3 vote).

Sources:

Salim’s conclusion

Human writing again. This output is about equal in quality to a policy brief of mine; it’s certainly on par with what I would expect from a research assistant. Even with the crutch provided by my published list, it wasn’t fooled and found two laws that I had missed. And it’s vastly more accurate than the other research I saw on this topic, which was performed by an intern at a trade organization, was terribly inaccurate, and was widely distributed to state legislators.

53 Comments

  1. Your blog has quickly become my go-to source for reliable information and thought-provoking commentary. I’m constantly recommending it to friends and colleagues. Keep up the excellent work!

Leave a Reply

Your email address will not be published. Required fields are marked *