user: ### NOW ANSWER:
Question: Which Lead Margin has a Poll Source of Rasmussen Reports/ Fox News?
Columns: ['Poll Source', 'Date administered', 'Democrat', 'Republican', 'Lead Margin']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['Reuters/Zogby', 'October 31- November 3, 2008', 'Barack Obama', 'John McCain', 0.0]
SQL:

assistant: SELECT MIN("Lead Margin") FROM "Table" WHERE "Poll Source" = 'Rasmussen Reports/ Fox News';