Question: who was the second president to be impeached
[{'answer': 'Clinton', 'provenance': [{'wikipedia_id': '1296149', 'title': 'Impeachment of Bill Clinton', 'start_paragraph_id': 0, 'start_character': 20, 'end_paragraph_id': 0, 'end_character': 27, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]