How would the VRA's redistricting implications play out with more minorities?

[muon2]

Whites are not a protected minority under the VRA. As to how Mississippi would have to be drawn... depends on communities of interest under the Gingles test.

A state has no obligation to draw more VRA section 2 districts than would be required to achieve a rough proportionality compared to the voting age population (Johnson v De Grandy- 1994). If MS were 55% black, the state could draw only 2 black-majority districts and not be in violation of the VRA.

[muon2]

Whites are not a protected minority under the VRA. As to how Mississippi would have to be drawn... depends on communities of interest under the Gingles test.

If this is true, that the VRA doesn't protect Whites, couldn't it face a possible legal challenge based on the "equal protection clause" of the 14th Amendment?  The Constitution is colorblind.

The VRA's constitutionality is tested many times - and yeah, it remains contentious in legal circles, and it is likely that it will one day be struck. Though probably not without some kind of major demonstration that it is no longer  necessary.

e.g. http://www.washingtonpost.com/wp-dyn/content/article/2009/06/22/AR2009062200771.html

The contentious part is section 5 that requires certain jurisdictions to be "precleared". That was the subject of the suit in the article. As the opinion noted, it's based on old data and old voting patterns.

Section two applies to all states equally, and with the Gingles test it automatically can take new voting behavior and demographics into account. I don't think many observers find that part as troublesome.