The New Majority Index (NMI)

Updated for 2024!

Race has historically been one of the most predictive data points about partisan political behavior. Since presidential exit polling began in 1976, 88% of African Americans have backed the Democratic nominee, and 56% of whites have supported the Republican nominee (no Democrat has ever won the white vote for president in the past 48 years).

Despite this statistical saliency and consistency, no national political analysts incorporate racial demographic data into their election ratings.

Whereas many political prognosticators aggregate polling data into statistical models and forecasts, the NMI does not use polls at all since they are dependent on an individual pollster’s highly subjective determination of which people are likely to vote in a given election, among other reasons. This “Likely Voter” lens completely misses efforts to change the composition of the voting pool by organizing and mobilizing infrequent voters. (This is why so many analysts and operatives failed to anticipate the Democratic wins in Georgia in 2020 and 2021 and the unexpected strength of Democrats in the 2022 midterm House of Representatives elections). 

The Cook Political Report has developed a Partisan Voter Index (PVI) that uses past presidential election results in a given district and compares that number to the national results of the presidential vote. PVI is a useful metric in that it relies on actual election results, but it doesn’t show the full picture of the partisan leanings of the eligible but non-voting adult citizens in a congressional district. 

The NMI goes beyond PVI and adds two additional key data points:

1. The full racial diversity of each individual congressional district, and

2. The voter turnout rates of each racial group in that district.

These additional data points are then added to the past presidential results in that district to arrive at the NMI. A full description of the methodology behind the index can be found here.

2024 Midterm Elections Big Picture — The Race to 218 Seats

• Currently, Republicans, in effect, control 221 seats in the US House of Representatives (“in effect” because some seats are currently vacant due to resignations, etc). 

• Democrats will need a net gain of four seats to take control of the House in November, assuming that each of the vacant seats is filled by a member from the same party. 

• In 2020, Biden won the most votes in 226 of the 435 congressional districts.

• How many incumbents of each party are or could be vulnerable depends on which set of data one looks at—polling data (FiveThirtyEight), past partisan election results (Cook Political Report), or voter turnout by racial group (Steve Phillips). The NMI shows that there are 81 vulnerable seats, 25 held by Republicans and 56 held by Democrats. 

• The NMI shows that there are sixteen Republican-held seats that are the most flippable as the Democratic Party charts a path back to power in the House of Representatives.