Possible Clues:

• Reactionaries one used to get on the train
• Those unwilling to accept new ideas
• Influential faction
• Dinosaurs go off with adult, after shaking T Rex died
• Conservative element
• Conservative element; dyed-in-the-wool types
• Faction not accepting new ideas
• Is not new to a drug problem involving long-standing members
• Conservative element in sentries about to retire?
• Conservatives behind the Times newspaper, not the Scotsman