The Portland Press Herald poll was conducted by Critical Insights, a Portland-based opinion research firm.

The company called 615 voters around the state from June 20-25. It used random landlines and cellphones and conducted personal interviews.

The results were statistically weighted to reflect the demographics of the state’s voting population.

The poll has a margin of error of 4 percentage points for results based on the entire sample, with larger margins for subgroups such as independent voters or older voters.

An additional 100 women were polled to provide additional data on women’s perspectives.