English Actress Emily Blunt recently became US citizen last month (August 2015) and stated in a filmed interview that she thought, "This was a terrible mistake" after watching our presidential debate (The Hollywood Reporter).
US citizenship can be revoked for "Falsification and Concealment of Relevant Facts: You must be absolutely truthful when filling out paperwork and answering interview questions related to the naturalization application process."
In a taped interview (Jimmy Kimmel) Emily Blunt admitted she was untruthful in the naturalization process... She stated that she had to renounce Queen Elizabeth II, "but I don’t actually, technically renounce her... You don’t have mean it, but just say it.”
Dishonesty in process is grounds for "denaturalization", so lets fix the "mistake".