Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_87 (poll_source VARCHAR, lead_margin VARCHAR)
### Question:
Which poll source has a lead of 17?
### Answer:
SELECT poll_source FROM table_name_87 WHERE lead_margin = 17