Well, it’s not this straightforward. I’m not sure where you got your numbers and percentages from, but working on the assumption that they are correct:
It also matters where the votes come from. If the remaining 40% is all clustered in California and New York, and they all are convinced to go out and vote, and also vote blue, that doesn’t have an effect on the outcome.
Also, look at the small margins that Biden won on the swing states according to https://www.npr.org/2020/12/02/940689086/narrow-wins-in-these-key-states-powered-biden-to-the-presidency. So what this could mean, assuming that the 4% holds generally, is that the 4% difference cause by split ticket voting is greater than the margin that Biden won in those swing states. So without winning those folks - those moderate Republicans - over, the Dems lose the Electoral College and thus the Presidency.
Well, it’s not this straightforward. I’m not sure where you got your numbers and percentages from, but working on the assumption that they are correct:
It also matters where the votes come from. If the remaining 40% is all clustered in California and New York, and they all are convinced to go out and vote, and also vote blue, that doesn’t have an effect on the outcome.
Why? Electoral College.
See this chart, showing that split ticket voting (in particular, folks who voted all Republican EXCEPT for the President, where they voted Biden) was about 4% out of everyone who voted in 2020: https://www.pewresearch.org/politics/wp-content/uploads/sites/4/2020/10/PP_2020.10.21_split-icket-voting_0-01.png
Also, look at the small margins that Biden won on the swing states according to https://www.npr.org/2020/12/02/940689086/narrow-wins-in-these-key-states-powered-biden-to-the-presidency. So what this could mean, assuming that the 4% holds generally, is that the 4% difference cause by split ticket voting is greater than the margin that Biden won in those swing states. So without winning those folks - those moderate Republicans - over, the Dems lose the Electoral College and thus the Presidency.