Continuing my new series on GOP defections in the battleground states. First it was Michigan, then Wisconsin. A big thanks to those who commented on previous diaries and helped refine the inputs and assumptions. This diary assumes the CNN early voter poll result for Pennsylvania, according to which 3% of early votes are going to 3rd party or candidates other than Harris or Dump.
Question: How Many Republicans Are Defecting to Harris in Pennsylvania’s Early Vote?
Background:
CNN’s poll of Pennsylvania released today reports that Kamala Harris is leading with 57% of the early vote, compared to 40% for Donald Trump.
NBC’s Early Voting portal page for Pennsylvania, using TargetSmart voter modeling, provides the party registration breakdown among Pennsylvania early voters as follows:
- Democrats: 58%
- Republicans: 32%
- Independents: 10%
Preliminary Assumptions:
- Democratic Voters: Voting 95% for Harris, 5% for Trump.
- Independent Voter Scenarios: Republican defection is estimated under five independent voter split scenarios: 65:31, 62:34, 59:37, 56:40, 53:43.
Results: Republican Defection Rates by Independent Voter Splits
| Independent Split |
GOP->Harris |
GOP->Dump |
| 65:31 |
8.39% |
91.61% |
| 62:34 |
11.29% |
88.71% |
| 59:37 |
14.19% |
85.81% |
| 56:40 |
17.10% |
82.90% |
| 53:43 |
20.00% |
80.00% |
Base Calculations
The Republican defection rates are derived from the following general formula, based on early voting data:
Key Variables:
- P_Dems: Percentage of early voters registered as Democrats (47%).
- P_Reps: Percentage of early voters registered as Republicans (42%).
- P_Inds: Percentage of early voters registered as Independents (11%).
- H_Dems: Percentage of Democrats voting for Harris (95%).
- H_Inds: Percentage of Independents voting for Harris (varies by scenario).
Objective: Solve for x, the percentage of Republicans voting for Harris.
Formula for Harris’s Total Early Voting Support:
61% = (P_Dems × H_Dems) + (P_Inds × H_Inds) + (P_Reps × x)
Rearranging, we solve for x in each independent scenario, where GOP->Harris = x and GOP->Trump = 1 - x.
