Probably 2 pts.
Mark my words. The 2020 Election will be a replay of the 1972 Nixon-McGovern debacle. That one was 62-38%. Remember McGovern lost his VP-nominee Eagleton because of the revelation about his Electro-Shock Therapy, and had to hand-pick Sargent Shriver. A 24% Blowout by Nixon. And that was after the Watergate Break-In in June of 1972. The equivalent of the Electro-Shock Therapy will be Biden’s total collapse in the first debate with Trump. His dementia will be on full display, and the only puzzlement will be why they stuck with him that long; the only thing that can explain it is that the DemRats will be ready with a socialist VP that they can 25th Amendment into the White House, if they win by somehow hiding Biden’s disqualification during the long campaign.