Tamil Nadu's ruling DMK is thinking of elevating Udhayanidhi Stalin -- son of Chief Minister MK Stalin - as the Deputy Chief Minister. He would be the second-in-command in the government, senior party sources have said. The elevation would be a key step in strengthening the second-rung leadership in party, sources said. Udhayanidhi Stalin has played a key role in the recent Lok Sabha election campaign that was swept by the DMK in the state.