For a glimpse of where artificial intelligence is headed in election campaigns‚ look to India‚ the world’s largest democracy‚ as it starts heading to the polls on Friday. An A.I.-generated version of Prime Minister Narendra Modi that has been shared on WhatsApp shows the possibilities for hyperpersonalized outreach in a country with nearly a billion voters. In the video — a demo clip whose source is unclear — Mr. Modi’s avatar addresses a series of voters directly‚ by name. Down the...