Table: election_results_1948
Columns: district
incumbent
party
first_elected
result
candidates

Question: What year was first elected william m. wheeler (d) unopposed?
SQL: SELECT "first_elected" FROM election_results_1948 WHERE "candidates" = 'William M. Wheeler (D) Unopposed'

Question: What district does  incumbent  james c. davis represent?
SQL: SELECT "district" FROM election_results_1948 WHERE "incumbent" = 'James C. Davis'