Maine Speaker of the House Sara Gideon is maintaining a slight edge in her effort to unseat longtime U.S. Sen. Susan Collins, R-Maine, according to a newly released poll.

The poll by the left-leaning Public Policy Polling surveyed 1,022 Maine voters on July 2-3 using both text messages and landline telephones. It found 46 percent favored Gideon and 42 percent favored Collins, while 11 percent said they were undecided. The poll has a 3.1 percent margin of error.

Maine House Speaker Sara Gideon Derek Davis/Staff Photographer

Gideon, a Democrat from Freeport, is widely considered the frontrunner among three candidates seeking the party’s nomination to challenge Collins, a Caribou native, in the July 14 primary. Collins, who is seeking her fifth term in the Senate, has no primary opponent.

The poll also suggests presumptive Democratic nominee Joe Biden had an 11-point lead in Maine over President Trump in the November election.

Based in North Carolina, Public Policy Polling conducts automated as well as online surveys nationwide both for clients and for a general audience. The political news and poll-tracking website fivethirtyeight.com give the firm an accuracy of 80 percent and a B grade. The polling arms of  Quinnipiac University and Marist College, by comparison, both had slightly higher accuracy rates and respective grades of B+ and A+.

A Public Policy Polling poll released in March also showed Gideon with a four-point lead in a hypothetical match-up with Collins in November. Since March, the Democratic field has narrowed by one, with Ross LaJeunesse, a Biddeford tech entrepeneur, leaving the race. Maine Democratic voters will choose between Gideon, Bre Kidman, a Saco attorney, and Betsy Sweet, a Hallowell-based lobbyist and activist.

Sen. Susan Collins, R-Maine Al Drago/Pool via AP

Of those surveyed in the latest poll, 38 percent said they were Democrats, 30 percent said they were Republicans and 32 percent said they were independent. That’s a slight over-sampling of Democrats and Republicans based on the latest information on voter registration, which shows 36 percent of the state’s 1.05 million voters registered as Democrats, compared to 27.5 percent as Republicans and 32.5 percent not enrolled in either party. The Maine Green Independent Party also has 42,242 registered voters.

The poll, released Monday, also slightly over-sampled female voters at 53 percent of respondents, compared to 47 percent who identified themselves as male. The most recent data from the U.S. Census Bureau, from 2019, shows females make up about 51 percent of the state’s 1.3 million population.

Collins is facing one of the toughest re-election campaigns of her career in a race that’s gained national attention and money. She has also faced increasing criticism from the left for her support of Supreme Court Justice Brett Kavanaugh, an abortion foe, and her vote to acquit Trump during impeachment proceedings earlier this year.

The new poll also found that only 36 percent of respondents approved of Collins’ job performance while 55 percent said they disapproved. But the poll also finds that Gideon, who collected more than twice as much as Collins in campaign donations between April and June, may still be struggling with name recognition statewide. The poll found 37 percent of respondents had a favorable view of her, while 37 percent had an unfavorable view and 26 percent said they did not know enough about her to have an opinion. Gideon is Speaker of the House and has led majority Democrats in the Legislature for four years.