Any single man can not force any Government to legalize bitcoin.  With the passage of time;when more and more people will come to the fold of bitcoin and will start using bitcoin for their payments; then majority of people will raise the demand to make the bitcoin legal currency.
May be then the Governments accept their demand and legalize it.
Also it is possible that Governments issue their own crypto digital currency having certain regulations and controls of Governments then the possibility to legalize the Bitcoin will be very low.