CREATE TABLE table_28667 ("District" FLOAT, "Incumbent" TEXT, "Party" TEXT, "Elected" TEXT, "Status" TEXT, "2010 Candidates" TEXT)

What is the party when 2010 candidates is gloria butler (d) unopposed?
SELECT "Party" FROM table_28667 WHERE "2010 Candidates" = 'Gloria Butler (D) unopposed'
SELECT "Party" FROM "table_28667" WHERE "2010 Candidates" = 'Gloria Butler (D) unopposed'