How and why we did this swing-state poll.

The Times/Siena College polls released on Sunday and Monday were conducted last week in six swing states that will likely decide the election: Arizona, Georgia, Michigan, Nevada, Pennsylvania and Wisconsin. Five of the states were won by Donald J. Trump in 2016 and flipped by Joseph R. Biden Jr. in 2020. Nevada, which has always been a close state, came within one percentage point in the 2022 U.S. Senate elections. .

These states also include some of the coalitions that will be critical next fall: younger, more diverse voters in states like Arizona, Georgia and Nevada; and white working-class voters in Michigan, Pennsylvania and Wisconsin who helped swing the election for Trump in 2016 and were central to Biden’s victory in 2020. They also offer some geographic diversity.

We interviewed 600 respondents in each state to ensure we had a large enough sample to speak to specific subgroups of voters within these states, including age, race and ethnicity, income, education level, and party affiliation. Taken together, these 3,600 respondents represent our largest sample size of swing state voters to date. This includes more than 700 undecided voters, a group that will be even more consequential within these crucial states.

This isn’t the first time we’ve focused on swing states this early in an election cycle. In 2019, the poll examined a similar set of states, reflecting the battleground states of the time. The political moment was slightly different, as Democrats were in the midst of a nominating contest that divided the party between liberals like Senators Bernie Sanders and Elizabeth Warren and a moderate Mr. Biden — and Mr. Trump was the incumbent president to beat.

However, the objectives of that poll were similar to this one. As Americans in key states across the political spectrum weigh their options, these polls shed light on the issues driving the election and voters’ interest in the leading candidates.