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

### Instruction:
What is the poll source when Jeff Sessions is at 58% and the date administered is July 31, 2008?

### Inputs:
table_name: table, columns: ['Poll Source', 'Dates administered', 'Democrat: Vivian Davis Figures', 'Republican: Jeff Sessions', 'Lead Margin']

### Response:
SELECT Poll Source FROM table WHERE Republican: Jeff Sessions = 58% AND Dates administered = july 31, 2008