Based on the inspection of the CSV files, here are the identified potential issues with missing columns:

### Issues Identified

1. **Missing Column in `rep_candidates.csv`**
   - **Evidence**: The `rep_candidates.csv` contains columns such as "Candidate", "State", "District", "Office Type", "Race Type", etc.
   - **Description**: The dataset appears to be missing a crucial column for "Party Affiliation" which is essential for understanding the candidate's political party.

2. **Missing Column in `dem_candidates.csv`**
   - **Evidence**: The `dem_candidates.csv` contains similar columns to `rep_candidates.csv` such as "Candidate", "State", "District", "Office Type", "Race Type", etc.
   - **Description**: Similar to the `rep_candidates.csv`, the dataset is missing the "Party Affiliation" column which is necessary for identifying the political party of each candidate.

### Example Issue Format

```json
[
  {
    "issue": "Missing column in rep_candidates.csv",
    "evidence": "The rep_candidates.csv contains columns such as 'Candidate', 'State', 'District', 'Office Type', 'Race Type', etc.",
    "description": "The dataset appears to be missing a crucial column for 'Party Affiliation' which is essential for understanding the candidate's political party."
  },
  {
    "issue": "Missing column in dem_candidates.csv",
    "evidence": "The dem_candidates.csv contains columns such as 'Candidate', 'State', 'District', 'Office Type', 'Race Type', etc.",
    "description": "The dataset is missing the 'Party Affiliation' column which is necessary for identifying the political party of each candidate."
  }
]
```

These issues highlight the need for the inclusion of a "Party Affiliation" column in both datasets to ensure completeness and usability.