CREATE TABLE table_21040 ("Poll Source" TEXT, "Dates administered" TEXT, "Democrat: Vivian Davis Figures" TEXT, "Republican: Jeff Sessions" TEXT, "Lead Margin" FLOAT)

On June 30, 2008 who what was the Republican: Jeff Sessions percentage?
SELECT "Republican: Jeff Sessions" FROM table_21040 WHERE "Dates administered" = 'June 30, 2008'
SELECT "Republican: Jeff Sessions" FROM "table_21040" WHERE "Dates administered" = 'June 30, 2008'