user: Question: What is the lead margin for McCrory when he has 49%?
Columns: ['Poll Source', 'Dates administered', 'Democrat: Beverly Perdue', 'Republican: Pat McCrory', 'Libertarian: Michael Munger', 'Lead Margin']
Types: ['text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['Rasmussen Reports', 'October 23, 2008', '47%', '51%', 'not an option', 4.0]
SQL:

assistant: SELECT "Lead Margin" FROM "Table" WHERE "Republican: Pat McCrory" = '49%';