Let's analyze the opposition to the Civil Rights Act of 1964 as presented in the table:
### Step-by-Step Analysis
1. Votes by Party:
- Republicans:
- Yes: 27
- No: 6
- Democrats:
- Yes: 46
- No: 21
2. Votes by Region:
- Northern States:
- Yes: 72
- No: 6
- Southern States:
- Yes: 1
- No: 21
### Summary of Opposition:
- Republican Party: 6 votes against the Act.
- Democrat Party: 21 votes against the Act.
- Northern States: 6 votes against the Act.
- Southern States: 21 votes against the Act.
By examining these numbers, the group with the highest number of 'No' votes is the residents of the Southern States with 21 votes against the Act.
Therefore, the correct answer is:
Residents of Southern states.