The Obama administration's stunning betrayal of medical marijuana patients claimed a new victim today. Delaware Gov. Jack Markell announced that he would halt the implementation of the state's medical marijuana dispensary program following a vague and threatening letter from U.S. Attorney Charles Oberly III. Oberly's letter, dated February 9 but made public today, says that patients and individual caregivers would not be federal enforcement priorities, but that entities distributing marijuana "could"…