Related Clues:

• Prefix with change or act
• Social starter?
• Side in an argument
• One who hasn't turned pro?
• Prefix with knock
• Planning to vote no
• Pt. of ICBM
• Knock or social attachment
• Encrypt?
• Debater's position, perhaps
• Prefix with trust
• Voting 'nay'
• Freeze beginning
• Protester
• No pro