CREATE TABLE table_43586 ("Poll Source" CLOB, "Dates administered" CLOB, "Democrat: Mary Landrieu" CLOB, "Republican: John Kennedy" CLOB, "Lead Margin" FLOAT)

Which organization administered the poll that showed a lead margin of 5.5?
SELECT "Poll Source" FROM table_43586 WHERE "Lead Margin" = '5.5'
SELECT "Poll Source" FROM "table_43586" WHERE "Lead Margin" = '5.5'