Actually the question you asked would not do not do complete justice to question that you had this mind.
In Indian general election election, any candidate could contest from as long as he could get endorsement from even a single elector in case he is member of a national party and 10 electors if he is an independent candidate, a job that is to easy to accomplish. His fighting election from Lucknow has very little relation with muslim % of that constituency. He is from western UP where there are large number of Muslims.
In state of UP, muslims constitute 19% of population and form largest monolith voting block. Hindu votes are divided among various castes and sects. Here Muslims have made a deal with Yadavs ( who constitute 7%) that they would support their party as long as Mulayam singh ( chief of SP, party of Yadavs ) support Jihad agenda.Recently a movie PK (Acted upon and funded by muslims) that is just which insulted and lampooned Hindu gods was made tax free in UP.Even if someone support unbridled free speech, he/she could not morally support state promoting hate speech against a religious group ( by giving tax breaks ) just because that group does not kill those who insult their Gods.
This voting block of 26% is too difficult to overcome by any other combination , and as you may know it from experience, 26% is more than enough to win any election in first past the pole system. They could be defeated only by a united rallying of Hindu votes like it occurred during last election when not even a single muslim was elected to Parliament from that State, an event that has low probability of occurrence.
Islamic radicals draw strength from this rather than their numbers. If India replaces Parliamentary system with Presidential, these people would lose all their political power.
BTW, UP is a dump. Every negative stereotype you may have come across about Indians is courtsey to Bhaiyyas from UP and Bihar. ( I am from UP, and know this pretty well ).