Richard Nixon was a Republican when he sent his destroyers in Arabian Sea.
Historically it is a known fact that except Bush Administration Dems have been more favourable to India compared to republicans.
However when we talk about 21st Century
Bush>Obama>Trump on India.
Bush was the most Pro India president probably after JFK. Trump in his initial years was too soft on China compared to Obama. Obama also executed OSama in Pakistan that changed the dynamics of US Pak relations.
At the moment both Dems & Republicans are pissed with China & public as well. So let's see how it goes.
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.