Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What was the sample size for polling on May 2-7, 2007 for Hillary Clinton?

### Inputs:
table_name: table, columns: ['Poll Source', 'Sample Size', 'Margin of Error', 'Date', 'Democrat', 'Republican']

### Response:
SELECT Sample Size FROM table WHERE Date = may 2-7, 2007 AND Democrat = hillary clinton