The Congress deliberately favored weakly qualified Dalit candidates over highly qualified ones

Evidence

From candidates who came from high caste Hindus, such as Brahmins and the allied communities, those with the highest qualifications were selected. In the case of the Non-Brahmins those with low qualifications were preferred to those with higher qualifications. And in the case of the Untouchables those with little or no qualifications were selected in preference to those who had. — Ambedkar, B R, Annihilation of Caste_ The Annotated…, 1328