user: Question: what is the maximum lead margin on August 5, 2008?
Columns: ['Poll Source', 'Dates administered', 'Democrat: John Kerry', 'Republican: Jeff Beatty', 'Lead Margin']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['Survey USA', 'October 28, 2008', '58%', '34%', 24.0]
SQL:

assistant: SELECT MAX("Lead Margin") FROM "Table" WHERE "Dates administered" = 'August 5, 2008';