What does mantle mean in government?

Excuse me, could you please clarify what 'mantle' means in the context of government? I've come across this term in some documents, but I'm not entirely sure how it's being used. Does it refer to a specific role or responsibility within the government structure? Or is it perhaps a metaphorical expression? I'm really curious to understand its significance and how it fits into the larger picture of governance. Could you enlighten me on this matter?