Rep. Bruce Poliquin and Democratic challenger Emily Cain are tied at 45 percent each in a Democratic poll of Maine's 2nd District obtained by Roll Call.
The poll, conducted by Normington Petts for the Cain campaign, shows similar results to a June poll that had the race tied.
Ten percent of voters were undecided in this month's poll, with a margin of error of plus or minus 4.9 percent. The poll surveyed 400 likely voters on both landlines and cellphones from Sept. 21-22. Democrats made up 24 percent of the sample, Republicans 31 percent and Independents 45 percent.
Donald Trump leads Hillary Clinton in the district, 44 to 40 percent. Minor party candidates took 10 percent of the vote. Trump is trying to contest the 2nd District since Maine is one of two states that splits its electoral votes by congressional district.
With both presidential nominees unpopular in the district, Poliquin and Cain have both worked to distance themselves from their party. Poliquin has dodged questions about the presidential race, refusing to answer whether he supports Trump.
Cain has endorsed Clinton, and Republicans are working to tie the former state legislator to the Democratic presidential nominee. But she has tried to appeal to Maine's ticket-splitting voters by touting her work with Gov. Paul LePage in her first television spot.
Democrats recruited Cain early for this race, expecting presidential-year turnout to give them their best shot at knocking off Poliquin. No incumbent has lost this district in 100 years.
Cain has had fundraising success this year, outraising Poliquin, but at the end of June, she still trailed significantly in cash on hand.