user: Question: Who were the candidates when the first elected was a Republican in 1998? 
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Results', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Illinois 1', 'Bobby Rush', 'Democratic', 1992.0, 'Re-elected', 'Bobby Rush (D) 84.1% Jason Tabour (R) 15.9%']
SQL:

assistant: SELECT "Candidates" FROM "Table" WHERE "First elected" = 1998.0 AND "Party" = 'Republican';