Though you can never "know" what someone is going to do, you can often predict so with some accuracy. Amitabh Bachchan has stated again and again since his 1980s' stint in the game, that he will not ever re-enter the world of politics. Over the years, he's likely had many an oppurtunity to go back on this, and there've certainly been times during which, financially, a new career might have benefitted him. As an actor, Bachchan's currently doing as well as anyone might ever wish to; financially, he's secure; personally, I don't think we've seen him take any steps toward politics again. The press (Indian and elsewhere) is often just a mighty cesspool of rumors and pure fabrications, and I doubt that this notion of Amitabh's running for President of Indian is anything more than unadulterated horse-shit.