They Key then is to ensure Bipartisan support for each other in both BD and India. India and BD both have two main political parties regardless of the regional players. In India its the Congress and BJP, while for BD, its AL and BNP.
While you will find a broad support for BD in both Congress and BJP, its the BNP that causes problems for India. Allowing greater trade between India and BD would make both Congress and BJP further be accomodative of BD concerns on various issues. One thing is certain, both Congress and BJP understand numbers and economy. Both know, their future depends on two factors-economy and security. And if BD raises its importance in the economic context, then you will find more bipartisan support for BD.
As far as security is concerned, AL is already trying to improve things, they have already said they will not allow BD to be used for anti-India activities. So things are on a mend here.
There is one issue-BNP.
They are a decidedly Islamist party which tries to undo absolutely anything or any deal that might be good for India. It takes steps that actually harm India. They are in cahoots with the Islamic militants, they are not in favour of putting for trial even the war crime accused in the Liberation War of BD. Indo-BD relations take a nose dive whenever BNP comes to power. They were in power when India actually started accusing BD of helping the insurgents in NE India in collusion with ISI.
What to do about that mate?