user: Question: What is the sample size of the poll taken on Dec 13-15, 2007 that had a margin of error of more than 4 and resulted with Republican Mike Huckabee?
Columns: ['Poll Source', 'Sample Size', 'Margin of Error', 'Date', 'Democrat', 'Republican']
Types: ['text', 'real', 'real', 'text', 'text', 'text']
Sample row: ['Quinnipiac', 1528.0, 2.5, 'Mar 16-18, 2008', 'Hillary Clinton', 'John McCain']
SQL:

assistant: SELECT "Sample Size" FROM "Table" WHERE "Republican" = 'Mike Huckabee' AND "Margin of Error" > 4.0 AND "Date" = 'Dec 13-15, 2007';