CLEVELAND (AP) — In an election year like no other, the first debate between President Donald Trump and his Democratic challenger, Joe Biden, could be a pivotal moment in a race that has remained stubbornly unchanged in the face of historic tumult.

The Tuesday night debate will offer a massive platform for Trump and Biden to outline their different visions for a country facing multiple crises, including racial justice protests and a pandemic that has killed more than 200,000 Americans and cost millions of jobs.

The health emergency has upended the usual trappings of a presidential campaign, lending heightened importance to the debate. But amid intense political polarization, comparatively few undecided voters remain, raising questions as to how, or if, the debate might shape a race that has been defined by its bitterness and, at least so far, its stability.

But the impact of the debate — or the two that follow in the weeks ahead — remains unclear.