Possible Clues:

• MLB sluggers who don't play the field
• ICE is part of it
• M.L.B.'s '10th men'
• T.S.A. overseer
• The TSA is part of it
• A.L. players who only bat
• Part of the cabinet since 2002, for short
• Govt. div. that includes 10-Across
• The TSA and ICE are part of it
• Some A.L. (but not N.L.) players