CREATE TABLE table_3568 ("District" FLOAT, "Incumbent" TEXT, "Party" TEXT, "Elected" TEXT, "Status" TEXT, "2010 Candidates" TEXT)

What is the highest numbred district that has brian w. thomas as an incumbent?
SELECT MAX("District") FROM table_3568 WHERE "Incumbent" = 'Brian W. Thomas'
SELECT MAX("District") FROM "table_3568" WHERE "Incumbent" = 'Brian W. Thomas'