Will Platner maintain his RCP polling lead over Collins for Maine Senate seat on June 30?

Democrat Graham Platner maintained his lead over Republican incumbent Sen. Susan Collins in the RealClearPolling average for the 2026 Maine Senate race as of June 30, 2026, with the aggregate showing Platner ahead 48.3 percent to 43.8 percent — a margin of 4.5 percentage points. Platner has led Collins in every public poll conducted in the race this cycle, with individual surveys placing his advantage between one and four points. A June UMass Lowell poll confirmed the slim but consistent edge. Collins, who has won reelection in Maine four times as a centrist Republican and is one of the few members of her party to have broken with Trump on multiple high-profile votes, has narrowed the deficit in recent months but has not overtaken Platner in any released survey. National forecasters continue to rate the race a toss-up given Maine's independent-minded electorate and Collins' strong personal brand. The community was essentially unanimous in expecting Platner to hold his polling lead, with 96 percent predicting yes — the most lopsided result of this resolution batch.