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

### Instruction:
What is Poll Source, when Democrat: Carl Levin is 61%?

### Inputs:
table_name: table, columns: ['Poll Source', 'Dates administered', 'Democrat: Carl Levin', 'Republican: Jack Hoogendyk', 'Lead Margin']

### Response:
SELECT Poll Source FROM table WHERE Democrat: Carl Levin = 61%