You only have to look at the regime of the DMK during 1969-74 when political opponents were murdered. They started the famous "Muster Roll" scam which was probably the first organized scam in TN. They even tried to kill Indira Gandhi because she had dismissed the DMK Govt in 1974. Why else were Karunanidhi and the DMK kicked out within 6 years and left to rot for 13 years? He is in power now by default because Jayalalitha does not have the charisma or sagacity of MGR.
There are many more things, but I don't want to waste my time in details. I know you are a DMK supporter Mr.Dinesh, but the facts don't cease to exist because they are ignored.