CREATE TABLE table_6634 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB)

Which Incumbent has a District of massachusetts 2?
SELECT "Incumbent" FROM table_6634 WHERE "District" = 'massachusetts 2'
SELECT "Incumbent" FROM "table_6634" WHERE "District" = 'massachusetts 2'