Re: Question about Indian Muslims..
It is not as if in a democracy, only 'muslim parties' need to represent muslims. All parties represent muslims just as they represent hindus, christians or sikhs or Tamilians, UPite or Bengalis. You could have parties that get support from only some of these religious or linguistic groups, but that does not preclude the support the mainstream parties have.
As for 'muslim causes', Indian muslims see only a few - Issues like the Gujarat riots; possibly the Palestine problem (90% of indian muslims will have no clue as to what the issue is or even where it is, much like with Pakistani muslims, I suspect, but let us put it in the basket); Iraq? maybe; issues like unsavouy treatment at US airports are not in the radar range because there have not been many reported incidents of Indian muslims undergoing similar treatment.
In all of the above, the 'non-muslim' parties & social organisations have been in the forefront of protests - be it the Gujarat issues or Palestine or Iraq. India officially supports Palestine on their demands. It was in deference to 'muslim opinion' that even Vajpayee refused to send the Indian army to Iraq. The ruling congress has officially condemned the US action in Iraq and so have most of the mainstream newspapers. Most major parties took to the streets to protest against the invasion of Iraq, but these are not bread & butter issues for the common Indian.