b'For the past few months, a single senator \\u2014 Tommy Tuberville \\u2014 has blocked hundreds of promotions in the U.S. military.\\n\\nKaroun Demirjian, a congressional correspondent for The Times, explains what\\u2019s behind the senator\\u2019s blockade, and why military leaders say it\\u2019s becoming a threat to national security.\\n\\nGuest: Karoun Demirjian, a congressional correspondent for The New York Times.'