It's hard to imagine that either of those groups will be as enthusiastic for the nearly septuagenarian, uncharismatic Hillary as they were for Obama, and it's largely on the strength of the support of these two groups that Obama won in both 2008 and 2012. It's not that these erstwhile Obama voters will migrate en masse to Trump, certainly, but rather that they just won't be sufficiently inspired to turn out on election day at all.
In fact, an article in the New York Times which describes the Clinton campaign's fretting over the lack of enthusiasm for their candidate among younger black voters:
When a handful of liberal advocacy organizations convened a series of focus groups with young black voters last month, the assessments of Donald J. Trump were predictably unsparing.A majority of African Americans is convinced - unfairly, I think - that Trump is a racist, so it's doubtful he can win as many of their votes as did George W. Bush, but Trump's surely counting on the possibility that African Americans and young people just won't turn out for Hillary in Obama-sized numbers either.
But when the participants were asked about Hillary Clinton, their appraisals were just as blunt and nearly as biting.
“What am I supposed to do if I don’t like him and I don’t trust her?” a millennial black woman in Ohio asked. “Choose between being stabbed and being shot? No way!”
“She was part of the whole problem that started sending blacks to jail,” a young black man, also from Ohio, observed about Mrs. Clinton.
“He’s a racist, and she is a liar, so really what’s the difference in choosing both or choosing neither?” another young black woman from Ohio said.
Young African-Americans, like all voters their age, are typically far harder to drive to the polls than middle-aged and older Americans. Yet with just over two months until Election Day, many Democrats are expressing alarm at the lack of enthusiasm, and in some cases outright resistance, some black millennials feel toward Mrs. Clinton.
The question of just how many young African Americans will show up to vote carries profound implications for this election. Mrs. Clinton is sure to dominate Mr. Trump among black voters, but her overwhelming margin could ultimately matter less than the total number of blacks who show up to vote.There's much more analysis of Hillary's difficulties in sparking enthusiasm in minority communities at the link. Maybe she'll soon be dusting off her southern patois again in order to pander to young blacks:
To replicate President Obama’s success in crucial states such as Florida, Ohio and Pennsylvania, she cannot afford to let the percentage of the electorate that is black slip far below what it was in 2012. And while a modest drop-off of black votes may not imperil Mrs. Clinton’s prospects, given Mr. Trump’s unpopularity among upscale white voters, it could undermine Democrats’ effort to capture control of the Senate and win other down-ballot elections.
Adding to the worries is a separate poll of African-Americans that Mr. Belcher conducted earlier in the summer indicating that Mrs. Clinton is lagging well behind Mr. Obama’s performance among young blacks in a handful of crucial states.
“There is no Democratic majority without these voters,” Mr. Belcher said. “The danger is that if you don’t get these voters out, you’ve got the 2004 John Kerry electorate again.”