Wulff has been one of the four deputy chairmen of the CDU party at the federal level since 7 November 1998 . He has also been a board member of the Konrad Adenauer Foundation since 2003 . Wulff has been one of the four deputy chairmen of the CDU party at the federal level since 1998 , and has been a board member of the Konrad Adenauer Foundation since 2003 .