You're right. BJP is taking a risk here. On the other hand, it's an amazing opportunity.
If seen in bigger context, you need to have political power to bring in changes you want. BJP should utilize this opportunity to strengthen it base in Karnataka. There must be a mix of pragamatism and ideals. You cannot go by just ideals. Look at Congress at center. How many and how strange bedfellows are there just to stay in power.