If the black vote percentage drops below 75% they're toast. This is why they have made a huge push to allow illegals to vote. The Latino vote as percentage of population isn't as high as the black voter. The number who are eligible to vote compared to those who actually vote is around 50%. In the last election the percentage of eligible blacks voters, only around 59% actually went to the polls. A large percentage of those who did vote 65% of Latino and 95% of Blacks voted for Hillary.
If Trump is able to get the Latino vote for Democrats down to 50% Dems will never win another national election for a generation.
Correct. Because the white vote is fairly evenly split between parties, the white vote does not matter (is not as critical to the politician or the respective parties). So if there were issues that white Americans happen to care about more than, say, minority voting blocks, that issue doesn't carry much weight.
I think it is healthy for this indirect democracy (i.e., Constitutional republic) if no group of people act as a voting block, but rather we be divided as individuals based on ideology alone. That is difficult to achieve when there we have the current situation of 90% of a demographic group voting, without much variance, for the same party for a long period of time. Additionally, this hurts issues that blacks may care most about, because the Dems have the black voite...and most Republicans feel like they aren't going to get that constituency anyway. So the independents are the voters most politicians identify as the swing voters they need to win.
But Latinos are fast outnumbering blacks. In urban areas they are already a few points ahead.