Del. Const. art. III, § 11 – County officers; qualifications; members of Congress, federal employees, and other officers holding dual office

(a) No person shall be elected or appointed to an office within a county who shall not have a right to vote for a Representative in the General Assembly and have been a resident therein 1 year next before the person’s election or appointment, nor hold the office longer than the person continues to reside in the county, unless herein otherwise provided.
(b) No member of Congress, nor any person holding or exercising any office under the United States, except officers usually appointed by the courts of justice respectively and attorneys-at-law, shall at the same time hold or exercise any office of profit under this State, unless herein otherwise provided.
(c) No person shall hold more than 1 of the following offices at the same time: Secretary of State, Attorney General, Insurance Commissioner, State Treasurer, Auditor of Accounts, Prothonotary, Clerk of the Peace, Register of Wills, Recorder, or Sheriff.