Let’s assume a 50/50 split of 20 voters to make the math simple, 10 each of R and D.
If 1 in 10 R voters didn’t vote, that would be a 9:10 split, a 47% - 52% split, a 5% difference. If that voter then voted D, it would be a 9:11 split, a 47 - 57% split. To get that 20% split, you’d need a second R voter to change sides for an 8:12 split, which simplifies to 4:6, or a 40% - 60% split, which is a 20 point spread.
According to the math above, you can see that I was wrong by confusing the 20% population of R voters and the 10% of all voters.
Let’s assume a 50/50 split of 20 voters to make the math simple, 10 each of R and D.
If 1 in 10 R voters didn’t vote, that would be a 9:10 split, a 47% - 52% split, a 5% difference. If that voter then voted D, it would be a 9:11 split, a 47 - 57% split. To get that 20% split, you’d need a second R voter to change sides for an 8:12 split, which simplifies to 4:6, or a 40% - 60% split, which is a 20 point spread.
According to the math above, you can see that I was wrong by confusing the 20% population of R voters and the 10% of all voters.