Question: who won popular vote in 2008 presidential election
[{'answer': 'Barack Obama', 'provenance': [{'wikipedia_id': '406859', 'title': '2008 United States presidential election', 'start_paragraph_id': 1, 'start_character': 153, 'end_paragraph_id': 1, 'end_character': 165, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]