Is the Republican party doomed on presidential level?

[Asian Nazi]

Of course not. Even if Democrats influx of hispanic immigrants helps them for the first few elections, the second generation of hispanic immigrants will definitely not be as kind to the Democrats.

Just like how all of the Hispanics that lived in the American Southwest for generations have completely assimilated into white American culture and vote solid R.

[Asian Nazi]

For the record I voted "yes".  But by "doomed" I think that the GOP is just in for a bit of a rough patch, like they were from 1932-1968, or the Democrats were from 1968-2008.  The next few cycles will be fairly even, since the Democrats still have a bit more room to fall among white millennials and in the South/Greater Appalachia.  But ultimately the influx of Hispanic and Asian voters + the dying off of the Silent Generation will hurt the GOP at the Presidential level, though maybe not as much as some would think.  Mexico is already taking back more immigrants than it's sending, and Hispanic birthrates are declining while white ones are increasing.  And Asian immigration is probably going to taper off a bit too.

Plus, barring a total collapse of the current political system, the GOP is not doing to disappear.  Even if the most extreme demographic projections turn out true, they'll still have a white Southern base to fall back on, just like the Democrats did during the 1920's, and will be in the best position to take advantage of any crises/screw ups on the part of the Democrat Party.