AUGUSTA — A new poll shows Democrat Sara Gideon ahead of Republican Sen. Susan Collins by four points in a hypothetical contest this November.

In the survey of 872 Maine voters by Public Policy Polling, Gideon led Collins 47 percent to 43 percent while both Democratic presidential contenders Bernie Sanders and Joe Biden led President Trump by 10 points in respective match-ups against Trump. The polling was conducted by landline phones and text messages from March 2 to 3.

Based in North Carolina, PPP is a left-leaning polling organization that 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 says PPP has an accuracy of 80 percent and gives the firm 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 recent Colby College poll of more than 1,000 likely Maine voters showed Gideon and Collins in a statistical dead-heat, with the would-be Democratic challenger edging Maine’s Republican senator 43 percent to 42 percent with 14 percent undecided.

Gideon, who is Maine’s Speaker of the House, is one of four Democrats seeking her party’s nomination this June to challenge Collins. PPP did not ask survey respondents about how Collins would fare against the other Democratic contenders, Betsy Sweet, Ross LaJeunesse and Bre Kidman. And while Gideon is widely regarded as the leader in the Democratic race, her nomination is not a foregone conclusion during a June primary that will feature ranked-choice voting.

Collins, who is seeking fifth term in the U.S. Senate, faces the toughest reelection campaign of her career in a race that is drawing national attention and money.

While she has enjoyed support from Democrats and independents in years past, the Republican appears to have lost considerable ground because controversial votes on Supreme Court Justice Brett Kavanaugh, a Republican tax cut bill and to acquit Trump during this year’s impeachment trial. Trump had a disapproval rating of 56 percent in the PPP poll compared to 42 percent who approved of the president.

PPP’s survey found that 57 percent of respondents disapproved of Collins’ job performance compared to 33 percent who approved, with 10 percent unsure or having no opinion. Survey participants were decidedly mixed on Gideon, however, with 34 percent viewing her favorable, 32 percent unfavorably and 34 percent not sure or saying they don’t know enough about her to have an opinion.

PPP oversampled both Democrats (39 percent) and Republicans (34 percent) while under-surveying unenrolled or independent voters (27 percent) in Maine.

As of last November, the most recent statewide data available from the Maine Secretary of State’s Office, there were a total of 1,048,279 active registered voters – 347,948 Democrats (33 percent), 285,627 Republicans (27 percent), and 371,305 unenrolled voters (35 percent).