The speaker mentions that when they are 'in a row', they can do impersonations more authentically, emphasizing the importance of living the character. They express difficulty in maintaining authenticity in impersonations when they are not in the right mindset. The speaker uses their Nelson Mandela impersonation as a base to transition into their Barack Obama impersonation, believing that Mandela taught Obama due to similarities in their voices, particularly the 'hyper lift'. They find it crucial to revert back to the Mandela impersonation whenever they struggle to maintain the Barack Obama impersonation, highlighting the connection between the two characters in their voice modulation.