She is the rare Republican who sometimes can boost her own popularity back home by keeping her distance from President Donald Trump, and she has perfected that delicate dance even as his tightening grip on the party has cost two of her Senate Republican colleagues their reelection.

Tuesday marked an especially significant moment for Graham Platner, the embattled veteran and oyster farmer, who is fighting to rebuild his credibility in a campaign rocked by controversy.

Republicans and Democrats in Nevada, North Dakota and South Carolina select their nominees on Tuesday, but much of the nation's political focus will be on Maine. Democrat Graham Platner is expected to emerge from the primary to take on five-term incumbent GOP Sen. Susan Collins. But Platner has faced one scandal after another during the campaign. Geoff Bennett discussed more with Alex Seitz-Wald.