Congressman Garrett obviously knows his history.
As a condition of surrender, General Grant, in behalf of the Union, pledged that Confederate veterans would be granted the same rights and privileges as Union veterans. Included were the same pension rights and the right to have the Confederate flag flying in veteran's cemeteries.
Thus, banning the Stars & Bars from veteran's cemeteries would abrogate the instrument of surrender -- as well as being totally dishonorable.
Men with honor and a sense of History. Always on the top of the list to be honored.