Maine Democrats weigh Platner controversy in key Senate primary

The real signal in Tuesday’s primaries will not be just who wins, but how comfortably they do. In Maine, Graham Platner’s test is whether he can emerge from a two-candidate Democratic race with enough margin to show that a late barrage of controversy has not damaged the party’s best chance to take on Susan Collins in November. In South Carolina, Lindsey Graham faces a different test: whether a Republican incumbent first elected in 2002 can clear a majority and avoid a runoff that would expose weakness in a state where Democrats have not won a Senate race since 1998.

For Maine Democrats, the first unanswered question is whether Platner’s support is broad enough to survive the final-days scrutiny over his past behavior toward women and a tattoo controversy. Platner, a first-time candidate who has drawn national attention, remains the likely nominee, but a narrow result over David Costello would suggest that unease inside the party is real and could carry into the general election against Collins on November 3. A stronger win would matter because Democrats see Collins as one of their clearest pickup opportunities in the fight for Senate control.

The second question is whether turnout points to a coalition that can hold together beyond the primary. Maine’s June 9 ballot also includes the governor’s race and all four U.S. House seats, making the day a broader test of the state’s political direction. Maine also uses ranked-choice voting in state primary elections for federal offices when more than two candidates are on the ballot, a system that can reward candidates who build broader acceptance rather than just a narrow base. In a race with only Platner and Costello on the Democratic side, the margin still matters: a decisive Platner win would look like a party rallying behind its standard-bearer, while a thinner one could read as a warning that Democrats are tolerating him, not embracing him.

The third question is on the Republican side in South Carolina: can Lindsey Graham avoid a June 23 runoff by winning outright? The state is heavily Republican, and the Senate seat, a Class II seat, will be on the November 3 ballot, but the size of Graham’s primary vote will still be watched closely as a measure of Donald Trump’s sway over GOP voters. A majority would reinforce Graham’s hold on a party that has moved sharply right; a runoff would keep the race alive and turn a routine re-election bid into a longer test of Republican loyalty.

Together, the two primaries offer a clean read on both parties’ futures. In Maine, Democrats are deciding whether a bruised outsider can still become their best shot at defeating Collins. In South Carolina, Republicans are deciding how much support remains for an incumbent who has spent decades in Washington, but still has to prove he can dominate his own voters.