What percentage of the Hispanic/Asian/Black/ vote will Republicans get this turn

[Likely Voter]

Well here is the trend...

          00   04  08  12
Black   9   11    4     6
Latino 35   44   31   27
Asian  41   43   35   26

My guess for 2016
Black   8
Latino 33*
Asian  33*

Which means the GOP will need 61%+ of the white vote to win

* A LOT depends on the GOP position on immigration. Polling has shown that support for a path to citizenship makes a big difference (and Bush's 2004 seems to back that up). I am assuming that the GOP nominee will not back a path to citizenship.

[Likely Voter]

RE: Asian vote in 2014
http://www.washingtonpost.com/blogs/monkey-cage/wp/2014/11/10/did-asian-americans-switch-parties-overnight-no/

[Likely Voter]

White: 62

Mitt Romney - who ran what some called 'the  last great white campaign and was running against a black man - got 59%. That was actually better than GW Bush who was the last GOPer to win the PV. Even Bush Sr. in the 1988 landslide win only got 60%.  Yet somehow you think Hillary will under perform John Kerry and Michael Dukakis? Seriously?

The GOPs only path to victory is the follow the last guy who won the PV (GW Bush) and find a way to appeal to non-whites. They don't need to win them, but they got to get into the game. Trying to squeeze more and more out of the shrinking white population is a losing strategy.

[Likely Voter]

The candidate matters, but the policies matter more. As I noted in this post...
https://uselectionatlas.org/FORUM/index.php?topic=211629.0

polling shows a 25 point swing for Rubio with Latinos based on his position on immigration reform, meaning he drops 25 points when he backed away from his support for a path to citizenship.

This is why Hillary is already campaigning on a path to citizenship.
http://www.cnn.com/2015/05/05/politics/hillary-clinton-immigration-electoin-2016/

The GOP are about to go through a primary process where that position will be toxic. None of them will come out and then pivot to be able to get the kind of support Bush got in 2004 (when he was unopposed in the primary and didn't have to pander to the anti-immigration crowd).

As for Asians, they have been voting closer and closer to Latinos in recent prez elections and these days and with there being more net migration with Asians, immigration is probably an even bigger issue with them.