user: Question: How many incumbents are there in the Georgia 8 district when the party is Democratic?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Georgia 1', 'Jack Kingston', 'Republican', 1992.0, 'Re-elected', 'Jack Kingston (R) 71.6% Oscar Harris (D) 28.4%']
SQL:

assistant: SELECT COUNT("Incumbent") FROM "Table" WHERE "Party" = 'Democratic' AND "District" = 'Georgia 8';