user: Question: What is the percentage for Brown when the lead margin is 26?
Columns: ['Poll Source', 'Dates administered', 'Democrat: Brian Schweitzer', 'Republican: Roy Brown', 'Libertarian: Stan Jones', 'Lead Margin']
Types: ['text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['Public Policy Polling', 'November 2, 2008', '62%', '36%', 'not an option', 26.0]
SQL:

assistant: SELECT "Republican: Roy Brown" FROM "Table" WHERE "Lead Margin" = 26.0;