Graham Platner and big races for governor: What to watch in Tuesday’s primaries

2026 ElectionGraham Platner and big races for governor: What to watch in Tuesday’s primariesFour states vote Tuesday, with Maine’s key Senate race capturing the most national attention and Donald Trump picking sides in South Carolina’s race for governor.Listen to this article with a free account00:0000:00Add NBC News to GoogleMaine Senate candidate Graham Platner defends his past on campaign trail01:38Get more newsLiveonShareAdd NBC News to GoogleJune 9, 2026, 5:00 AM EDTBy Ben Kamisar, Bridget Bowman and Adam EdelmanTwo free-for-all primaries for governor in Maine and South Carolina are the most competitive races on the ballot in Tuesday’s primaries, while Maine’s Senate race has captured national attention as voters head to the polls in those states, as well as Nevada and North Dakota.Subscribe to read this story ad-free Get unlimited access to ad-free articles and exclusive content.Maine Democrat Graham Platner isn’t facing much of a challenge on the Senate ballot, but how he weathers a slew of controversies looms over one of the most competitive races in the battle for the Senate. While Democratic Gov. Janet Mills is still on the ballot, she suspended her bid weeks ago after she struggled to gain traction and ran out of money, and Platner is expected to prevail.Meanwhile, open races for governor are on tap in South Carolina and Maine, and both parties will choose nominees in a handful of key battleground House districts, as well as in safe seats where Tuesday’s primaries will all but cement the winners in the fall. Here’s what to watch across Tuesday’s elections, including where there’s more to glean than just the results — especially in Maine. It’s all about the marginThe drama in two Senate primaries on the ballot Tuesday, in Maine and in South Carolina, is not about who will win but about whether the primary margins show any signs of weaknesses for the nominees.Platner had been able to build a significant financial and polling lead over Mills before she suspe...