Gideon, who is one of four Democrats running in a June primary for the nomination to face Collins in November, had 43 percent of support in the survey. The Republican incumbent had 42 percent support with another 14 percent of voters undecided. The poll was conducted earlier this month and had an error margin of just over 3 percentage points…

Collins’ seat has been targeted by more than $10 million in ads since last year, with much of that spent by Democrats and allied groups to hammer the Republican incumbent representing a blue-leaning state who became a top target for liberals after her 2018 vote for U.S. Supreme Court Justice Brett Kavanaugh.

The Maine senator’s popularity has waned in a heavily nationalized environment. A survey released last month by Morning Consult found that Collins had the highest disapproval rating of any senator, with her approval rating down from 67 percent in early 2017 to 42 percent late last year. She won her 2014 re-election campaign with more than two-thirds of votes.