Question

how is the power sharing between the union government and the state government basic to the structure of constitution

Answer 1

The sharing of the power b/w union govt. and state govt. happens in a very systematic manner. For the sharing of power different list are made by the constitution i.e state( only for sate govt.) , concurrent ( for both central and state govt.), residual (for central govt.) and union (central govt.).only these can alone make the regarding rules for the subject in their lists

And also the constitution lays the power of  the sate govt. and central govt. Individually