; and (B) by striking the President may retire and inserting the Mayor may retire . (d) Call for duty (1) Section 45 of such Act (sec. 49–103, D.C. Official Code) is amended by striking , or for the United States Marshal and all that follows through shall thereupon order and inserting to order . (2) Section 46 of such Act (sec. 49–104, D.C. Official Code) is amended by striking the President and inserting the Mayor of the District of Columbia . (e) General courts martial Section 51 of such Act (sec. 49–503, D.C. Official Code) is amended by striking the President of the United States and inserting the Mayor of the District of Columbia . 3. Retention of Presidential authority over use of National Guard of the District of Columbia to respond to homeland defense emergencies (a) In general Chapter 9 of title 32, United States Code, is amended by adding at the end the following new section: 909. Control of National Guard of the District of Columbia for homeland defense activities Notwithstanding the authority of the Mayor of the District of Columbia as the Commander-in-Chief of the National Guard of the District of Columbia, as provided by section 6 of the Act entitled An Act to provide for the organization of the militia of the District of Columbia, and for other purposes , approved March 1, 1889 (sec. 49–409, D.C. Official Code), the President retains control over units and members of the National Guard of the District of Columbia to conduct homeland defense activities that the President determines to be necessary and appropriate for participation by the National Guard units or members. . (b) Clerical amendment The table of sections at the beginning of such chapter is amended by adding at the end the following new item: 909. Control of National Guard of the District of Columbia for homeland defense activities. . 4. Conforming amendments to title 10 , United States Code (a) Failure To satisfactorily perform prescribed training Section 10148(b) of title 10, United States Code, is amended by striking the commanding