Many of the recent cases, including the Aligarh case and the other Uttar Pradesh case, involve lower-caste, or Dalit, victims.

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Congress triumphed in state elections last November and was regaining support among Muslims and lower-caste voters in Uttar Pradesh, India's biggest state.

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Lower-caste politicians have become national power-brokers by astute appeals to caste loyalty.

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The new plan would set aside an additional 27% of places in educational institutions for Other Backward Classes (OBCs) - lower caste Hindus and other traditionally disadvantaged groups.

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OBCs - a collection of caste groups lower down in the hierarchy - accounted for 3.8% of the directors.

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