CREATE TABLE table_38456 ("Poll source" TEXT, "Dates administered" TEXT, "Roy Barnes" TEXT, "Thurbert Baker" TEXT, "DuBose Porter" TEXT, "David Poythress" TEXT, "Undecided" TEXT)

What is the DuBose Porter with Roy Barnes at 54%?
SELECT "DuBose Porter" FROM table_38456 WHERE "Roy Barnes" = '54%'
SELECT "DuBose Porter" FROM "table_38456" WHERE "Roy Barnes" = '54%'