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

### Instruction:
What is the source of the poll that had Republican: Dino Rossi at 46%, Democrat: Christine Gregoire at 50%, and the lead margin was larger than 3?

### Inputs:
table_name: table, columns: ['Source', 'Dates administered', 'Democrat: Christine Gregoire', 'Republican: Dino Rossi', 'Lead Margin']

### Response:
SELECT Source FROM table WHERE Republican: Dino Rossi = 46% AND Lead Margin > 3 AND Democrat: Christine Gregoire = 50%