WASHINGTON (AP) — A key question looms for vulnerable Republican senators this election: If Donald Trump loses and loses big, can they still survive?

With 11 weeks until Election Day, Trump’s declining standing in the polls has GOP Senate candidates preparing for the worst. They’re maneuvering to put as big a margin as they can between themselves and the top of the ticket.

Some strategists foresee a historic Trump loss and the need to outrun the presidential nominee by at least five to 10 percentage points in states like Pennsylvania, Ohio, New Hampshire and Florida, if Senate incumbents are to prevail. Such margins can be achieved, but it’s not easy, and most Republicans say there’s a limit to how big Trump can lose without taking down nearly every vulnerable congressional incumbent.