CREATE TABLE table_18175 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB, "Candidates" CLOB)

What district is Mac Collins an incumbent in?
SELECT "District" FROM table_18175 WHERE "Incumbent" = 'Mac Collins'
SELECT "District" FROM "table_18175" WHERE "Incumbent" = 'Mac Collins'