CREATE TABLE table_75640 ("Poll Source" TEXT, "Date" TEXT, "Candidate" TEXT, "Support" TEXT, "Consider" TEXT, "Oppose" TEXT, "Unsure" TEXT)

What percentage of people were opposed to the candidate based on the WNBC/Marist poll that showed 8% of people were unsure?
SELECT "Oppose" FROM table_75640 WHERE "Unsure" = '8%' AND "Poll Source" = 'wnbc/marist poll'
SELECT "Oppose" FROM "table_75640" WHERE "Poll Source" = 'wnbc/marist poll' AND "Unsure" = '8%'