user: Question: What district was a Republican first elected in 2000?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Results']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['Missouri 1', 'William Lacy Clay Jr.', 'Democratic', 2000.0, 'Re-elected']
SQL:

assistant: SELECT "District" FROM "Table" WHERE "First elected" = 2000.0 AND "Party" = 'Republican';