It’s now official: India is boycotting the Commonwealth conference, a meeting of the heads of state of former British colonies, which is being held in Sri Lanka this week. The decision has its roots in domestic politics, as politicians look forward to next year’s election, and it also shines a light on India’s often bewildering internal affairs.As Salman Khurshid, India’s foreign minister, said to a French journalist, the decision to boycott the conference is all about Tamil Nadu, a state on India’s southwestern coast that is home to 62 million Indian Tamils. “There’s a lot happening at home right now,” he said. “There were points of view of our colleagues and other parties from Tamil Nadu. They have very strong opinions about how we should deal with this situation that’s the post-conflict situation in Sri Lanka.”Indian Tamils are closely related to Sri Lankan Tamils, and politics in Tamil Nadu are frequently affected by the island across Palk Strait. Sri Lankan Tamils came off badly in the civil war that consumed the island for decades, and Indian Tamils always took it personally if New Delhi chose to support the Sri Lankan government over the beleaguered Tamils, which it often did in the form of weapons and political support for the government. This has sometimes made the relationship between political parties in Tamil Nadu and New Delhi somewhat distant in the past.As one of the more developed and successful Indian states, Tamil Nadu matters a lot in national politics. It has nearly the population of Turkey and the second largest economy among Indian states. Its politicians are some of India’s more recognizable: the current chief minister, J. Jayalalithaa, a former movie star, is on her fourth stint in the position. She frequently causes problems for the national government in New Delhi over issues with Sri Lanka. Along with the heads of other powerful regional parties, like Mamata Banerjee in West Bengal, Jayalalithaa is courted and wooed by politicians angling for the prime minister’s seat.And thus, the ruling Congress party in New Delhi decided that angering Jayalalithaa by overlooking her party’s concerns about human rights in Sri Lanka would be unwise. There is, after all, an election approaching.These regional parties and their interests are immensely important in Indian politics, but few foreigners grasp the dynamics. Imagine if Texas suddenly had 72 million people in it, and the vast majority of them were frequently preoccupied with a large population of ethnic Texans across the border in Mexico who were being oppressed and marginalized by the Mexican government. The triangular relationship between Austin, Washington, and Mexico City, not to mention between presidential hopefuls and the Texas politicians who could deliver some of those 72 million votes, would become very hairy indeed.