Before 1990, India had been mostly ruled by Congress governments at both centre and state. As a result, most state governments were subservient to the central government. State governments under Congress rule mostly acted according to the wishes of the central government. Few state governments that were ruled by non-Congress governments were in constant threat of dismissal by the Centre.
However, after 1990, centre state governments changed significantly. The Congress lost its dominant position in the Centre. Many regional parties became coalition partners in the Central government. As a result, the Centre could no longer control state governments as they used to do earlier. Hence, state governments became more autonomous and assertive. Centre-state relations became one of equals, as it should in a federal system.