U.S. EV adoption rates continue to rise overall, but vary significantly by state, according to a new J.D. Power study.

On a nationwide basis, EV adoption is rising steadily in the U.S., with EV sales now representing 8.6% of U.S. new-car sales, according to the study, which is based on data collected through August 2023.

However, the U.S. is being split into "two camps" when it comes to EV adoption, according to J.D. Power. Some states have promoted EV adoption with incentives and infrastructure projects, while others haven't—and it's beginning to show in the sales numbers.

U.S. EV adoption rates for the first half of 2023 (via J.D. Power)

U.S. EV adoption rates for the first half of 2023 (via J.D. Power)

The 10 states with the highest overall EV adoption rates—California, Washington, Hawaii, Oregon, Nevada, Maryland, Arizona, Colorado, Utah, and Massachusetts—saw continued growth in the first half of 2023, with rates climbing year-over-year.

Meanwhile, in the states with the lowest rates of EV adoption—Michigan, Iowa, Kansas, Arkansas, Mississippi, Wyoming, Louisiana, South Dakota, West Virginia, and North Dakota—adoption rates actually declined in the first half of 2023, according to J.D. Power, despite the overall growth nationally.

This means that, while California aims to end sales of new vehicles without charge ports in 2035, North Dakota will have just 19% EV sales by that year, according to the study.

2023 Ford F-150 Lightning

2023 Ford F-150 Lightning

Most states with EV adoption rates that appear to be going down are "red" states—including several favored by the U.S. supply-chain push for EVs. In contrast, "blue" states are well represented among the top EV adopters, and they carried more than 75% of U.S. EV sales in 2021.

However, analysis of EV sales from 2021 found that EV sales weren't closely related to sales mandates—typically thought of as a blue-state policy. And despite all this, and the divide in Congress, polls have found bipartisan support for policies supporting EV adoption.