TBH, US simply has to keep it's own interest in mind to not antagonize India.
While Pakistan may have been important to US and still may be, what's more important?
Preventing and maybe even furthering the collapse of a dominant China in Asia or a pet dog which can be replaced by any number of dogs?
Not to mention this pet dog also keeps biting it's owner's hand and will switch allegiance to China in a heartbeat (It's so obvious, I feel redundant for pointing it out).
China's economy will never blossom if India takes over GB and wins or even stalemates a war. It'll falter and fail.
US will finally be able to subdue it effectively and end any chance of getting replaced as the biggest economy very soon.
As for Republican favoritism, remember, democrats were pro-India when India had a so-called democratic counterpart (INC) in place. It's just ideological bias, nothing more.
I hate to sound like a snake oil salesman but if US really wants to maintain it's hegemony or even slow it's erosion, it'll have to choose India over the other 2 neighbors.