user: Question: Name the number of lead margin for republican joe kenney being 31%
Columns: ['Poll Source', 'Dates administered', 'Democrat: John Lynch', 'Republican: Joe Kenney', 'Lead Margin']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['Survey USA', 'October 29–30, 2008', '65%', '28%', 37.0]
SQL:

assistant: SELECT "Lead Margin" FROM "Table" WHERE "Republican: Joe Kenney" = '31%';