Amir wants to be a politician. This is all a nice way to get himself into the middle class's good books to be the next Shri Dutt or Chiranjeevi etc. KBC made Amitabh Bachhan a household name again after his disastrous movie comeback, and umpteen debt issues. Similarly, via this stuff, Aamir wants to rebrand himself as a thinking social activist + celebrity.
Unfortunately for him, in the north, his charisma and PR will get him only so far. The guy is much smarter than the mid life crisis SRK or from one brawl to the next party Salman. But manufactured hype only goes so far.
Real politics is dirty, brutal and no holds barred. Given his so called liberal leanings etc, he may be a good "face" for the INC. But a face is all he can aspire to be as all said and done, the INC is run by a combination of dynasty & money. Aamir will not be anymore important than a Jayaprada was in the Samajwadi party.
If he becomes an independent, then his power will be limited.
All said, he's a very shrewd guy with a political future in mind, but its not going to be easy for him.