HOT TAKE: Delimitation is justice, current seat distribution is unjust.
Tamilian btw. Delimitation as originally proposed raises the overall seat count from 543 to 850 in the Lok Sabha in accordance with 2011 census. Tamil Nadu and several other states argue that the population proportion model is not right considering they are "losing say" owing to population growth decline which is claimed to result from government birth control policies being successful in southern states
The same argument that the southern states are using can be used exactly analogously for other group identities such as educated/not, rich/poor, castes, religions to claim that the group identity that followed birth control better deserves equal representation along that group demarcation. For example: all rich people should have same say as poor people despite poor people drastically outnumbering the rich on the grounds that they successfully followed birth control. So along which group identity do we expect equal say?
The answer is none, as constitutionally we decided on the individual citizenship identity as being the grounds for vote value. 1 person 1 vote. In the proposed delimitation, 1 person gets 1 vote, so a Tamilian has equal vote value with any other Indian in India.
So when southern governments say we are losing say, that is purely clever framing and misdirection, we are getting exactly the say we are entitled to. 1 person 1 vote and so is UP and Bihar. So we losing say is blatantly false. The only relevant say is individual say and we are losing none of that. Exactly getting what we deserve and are entitled to. A smaller group of people having lesser say in voting than a larger group of people is a fact in democracy, a feature not a bug. A policy that affects 1000 UP people and 200 Tamil people should be decided based on 1000 votes from UP people and 200 votes from Tamil people because the policy affects 800 more UP people than Tamil people and there are 1000 says there and only 200 here. Anybody can claim a minority group identity and ask for equal group representation and consequent vote value increase under the erroneous argument of TN govt's argument.
Now addressing the GDP argument. Higher GDP benefits Tamil people first because they are the ones earning more. So does development and all these other things. Only shared benefit is the higher tax paid, the point of tax is to redistribute wealth from rich to poor, and the economic group identity is the relevant identity to study or assess taxes. If we quibble like this, then we must also recognize that for 1 Tamil soldier in the Indian army, there are more soldiers in the Indian army from UP and this is an unquestionable invaluable contribution to the whole country. If you talk taxes, then pay for all their more soldiers and deaths and go bankrupt.
Additionally, read about causes of lowered birth rates, spoiler: the government is lying blatantly, the biggest causes are not govt policies for birth control, but women's education and participation in the workforce. Read.
Summary: Principle: Under-representation meaning: 1 person getting less than 1 vote. Over-representation meaning: 1 person getting more than 1 vote. Adequate-representation meaning: 1 person 1 vote. We are adequately represented under delimitation.