Sen. Jon Tester (D-MT), one of several battleground-state Democrats up for reelection in the Senate, said on Monday that President Joe Biden needs to show he can handle a second term amid questions about his mental fitness.

Despite the criticism and representing a red state that Biden lost by 16 percentage points in 2020, the third-term senator ultimately stuck by him in the face of calls from other Democrats for the president’s withdrawal from the race.