Abstract: This archival study sought to determine if certain constituent demographics in state legislative districts were associated with higher levels of Democratic state legislative representation (compared to Republican representation). It also sought to determine if demographic trends at the Congressional level were generally consistent with those at the state legislative level. The analysis used state legislators elected in or as of 2020 and 2019 census data to look at indicators of race, income, and education and their association with partisan representation.

Race and Representation.

Nationwide:

• All races combined: Across all state legislative districts in the United States¹ in the dataset, as the percentage of total non-white racial diversity within the district increases, the likelihood of being represented by a Democratic state legislator increases.
• Races broken out: Similarly when race is broken out as a set of distinct variables, we find that as the percentage of distinct-race population increases, the likelihood of being represented by a Democratic state legislator (compared to a Republican state legislator) increases for all racial and ethnic minority groups. White people were the only racial group that was significantly more likely to be represented by Republicans .

Quartiles:

• All races combined: We sorted all state legislative districts into quartiles based on percentage of non-white population. Of the districts in the top quartile of percentage of racial/ethnic minority population, 86.55% are Democratically represented.
• Races broken out: We also sorted all state legislative districts into quartiles for each of 4 ethnic and minority groups (Black/African American, Hispanic/Latino, AAPI, Native American). When looking at the upper quartile for each group, Democrats represent at least about two thirds of districts in each top quartile for three such groups. However, an interesting outlier is that Democrats only represent 32.86% of the upper quartile of districts with the highest percentage of Native Americans living there². It should be noted that so few districts have a concentration of 50%+ Native Americans that the upper quartile of districts with the highest concentration of Native Americans ranges from 0.6-82.5%, meaning that even districts with less than 1% Native American residents fall into the top 25% of districts with the most Native American residents. This indicates that there are few districts with a majority Native American population (see footnote 2).

• These trends regarding the relationship between race/ethnicity and partisan representation generally seem to track trends at the Congressional level.

• Top 1% of Districts:
  • All races combined: We sorted all state legislative districts in numerical order by non-white racial diversity population and looked at the top 1% of districts. Of the upper 1% of districts in terms of percentage of racial and ethnic minority population, 94.29% are Democratically represented.

• Races broken out: We also examined the concentration of residents who identify as a specific racial/ethnic minority in top 1% of districts for each of the same 4 racial/ethnic minority groups.
  • Democrats represent 88%+ of the top 1% of districts with the largest percentage of AAPI, Black, and Latinx constituents and 51.43% of the districts with the largest percentage of Native American constituents.

Income and Representation.

Nationwide:

• • Median income: Across all state legislative districts in the dataset, Democratically-held state legislative districts appear to represent both the poorest and richest districts, while Republicans tend represent the majority of people in the middle income range. This indicates that Democratic representation does not increase linearly based on median income, but it dominates at the extremes. Ultimately, both parties have very similar national median incomes, with Democrats slightly edging out Republicans ($64,994.96 to $63,453.37 respectively).
  • Income levels broken out: As the percentage of the population making under $30,000 per year increases, representation by Democratic state legislators increases. As the percentage of the population making over $50,000 per year increases, representation by Democratic state legislators decreases in the middle but increases when the 70%+ of the population is making over $50,000 a year.

Quartiles:

• • We sorted all state legislative districts into quartiles based on each of the following variables: median income, % of district population making less than $30,000 a year, % of district population making more than $50,000 a year, and % of the district population living below the poverty level.
  • Democrats represent a higher percentage of districts with the highest median income (52.98%) compared to Republicans, the highest percentage of population making under $30,000 compared to Republicans (55.02%), and 64.11% of the districts with the highest concentration of folks in the census category for “living in poverty.” Republicans barely edge out Democrats on representation of districts with the highest concentration of folks making over $50,000 (49.83% vs 49.48% respectively), but still represent fewer than half the districts in this category.

• These trends regarding the relationship between income and partisan representation generally do track trends at the Congressional level, but the trends towards Democrats representing more wealth are more pronounced at the Congressional level and the trends towards representing more impoverished folks are more pronounced at the state legislative level.

• Top 1% of Districts:
  • We sorted all state legislative districts in numerical order and determined what percentage of the top 1% of districts are held by Democrats for the following variables: median income, % of the district population making less than $30,000 a year, % of the district population making more than $50,000 a year, and % of the district population living below the poverty level.
  • Democrats represent the majority of both the highest median income and % of over $50,000 districts (78.57% of upper 1% of median income districts; 54.29% of upper 1% income over $50,000 districts). Democrats also represent the majority of districts with the largest percentage of people living in poverty (91.43% of the top 1% of impoverished districts) and people making under $30,000 (91.43% of the top 1% of districts with the largest percentage of people making less than $30,000 a year).

Education and Representation.

Nationwide:

• • As the percentage of people with a bachelors’ degree increases in a district over 50%, representation by Democratic state legislators increases. The story is a bit murkier in districts where people with bachelor’s degrees do not make up 50% or more of the vote. However, it is clear that, when college educated folks make up 50% or more of the population in a district, that district is much more likely to be represented by a Democrat than a Republican.

Quartiles:

• • Democrats represent 63%+ of the state legislative districts in the upper quartile of districts by % of people who hold a bachelor’s degree and % of people who hold a graduate or professional degree.

• These trends regarding the relationship between education and partisan representation generally track trends at the Congressional level.

• Top 1% of Districts:
  • Democrats represent 90.00%+ of the top 1% of districts with the largest percentage of both college educated and graduate or professional school educated constituents.

• Democrats represent 25.71% of the top 1% districts with the highest percentage of constituents with a high school diploma as their highest degree.

Limitations: This data is archival and is not an exhaustive examination. More research is needed to determine if these trends persist over time, and if other trends exist that are not currently explored here, like those relating to age or gender. The current research presents an interesting starting point in exploring how demographics and partisan representation intersect at the state legislative level, and how those trends compare to those seen at the congressional level. More research will help to determine if these same trends were present in the past or if they extend into the future.

¹All state legislative bodies in the US were included other than the New Hampshire house, as we could not obtain complete numbers for the New Hampshire house from our census source.
²Native Americans are the smallest racial and ethnic minority group included as a category in the census data. See upcoming white paper for more information about this.