The party in charge is a Hindutva oriented party and the party in opposition is also a Hindu oriented party.
We would prefer a situation where the ruling party is a hardcore Hindutva based party and the party in opposition is also a hardcore Hindutva party.
In that way each can scratch the other's back. And the nation moves forward with policies getting implemented with minimum fuss.
Which is why in addition to the BJP and Shiva Sena we have the NATIONAL DEMOCRATIC WORKERS PARTY which will snatch votes away from Congress, Communists, Janata Dal etc.