Possible Clues:

• One who leaves régime in chaos?
• October Revolution figure
• Defector, e.g.
• Rudolf Nureyev, e.g.
• Nabokov, e.g.
• A political exile from regime
• Solzhenitsyn, e.g.
• Political refugee, especially a royalist fleeing the French Revolution
• New arrival
• Regime change might produce such a person