How much time does the GOP have left (demographically)?

[Higgins]

Looking only at the Presidential level, how much time should the GOP have left to capture the White House with their current coalition? I've read the Religious Right is failing in numbers and influence; the numbers of both White and non-White Hispanics are rising and both groups tend to vote Democrat. Is there any estimated point at which the GOP's White non-Hispanic base will no longer be sustainable to win the Presidency?

[Higgins]

Economics is what will do the GOP in if they don't adapt; though demographic and generational change both play an auxiliary role in this situation.

You don't think the GOP brand is already tarred as the party of "Rich and White"? Even if they turn to economics, I feel that stigma will (hopefully) kill them among younger people in years to come.

[Higgins]

I predict the GOP will win 80-90% of the white vote 20 years from now.

Why? Younger voters tend to be more Democratic leaning.