India has begun counting more than 640 million votes in the world’s largest democratic exercise. The count Tuesday was widely expected to return Prime Minister Narendra Modi to a third term after a decade in power. The 6-week election was seen as a referendum on Modi. If he wins, it will only be the second time an Indian leader has retained power for a third term after Jawaharlal Nehru, the country’s first prime minister. Exit polls have projected a comfortable win for Modi’s Hindu nationalist Bharatiya Janata Party and its allies over a broad opposition alliance led by the Congress party and its main campaign leader, Rahul Gandhi.