WASHINGTON (AP) — President Joe Biden’s conduct behind closed doors, in the Oval Office, on Air Force One and in meetings around the world is described in the same dual way by those who regularly see him in action.

He is often sharp and focused. But he also has moments, particularly later in the evening, when his thoughts seem jumbled and he trails off mid-sentence or seems confused. Sometimes he doesn’t grasp the finer points of details. He occasionally forgets people’s names, stares blankly and moves slowly around the room.

Biden’s occasional struggles with focus may not be unusual for someone his age. But at 81 years old and seeking another four years in the White House, the moments when he’s off his game have taken on a fresh resonance following his disastrous debate performance against Republican Donald Trump. The president appeared pale, gave nonsensical answers, stared blankly and lost his train of thought.

The June 27 faceoff alarmed Democrats and his financial backers, in part, because Biden seemed so much worse than during the almost routine moments when he’s less sharp. And that has raised questions about whether he’s up for a campaign that’s only going to get nastier and whether he can effectively govern for another four years if he wins.