Black votes matter as Sanders runs into a perfect storm

Democratic presidential candidate, Sen. Bernie Sanders speaks at the University of South Carolina, Tuesday, Feb. 16, 2016.

Bernie Sanders couldn't have asked for a better electorate than the one he saw in New Hampshire. It was mostly white - a group with which he does much better. It was 40 per cent independents (same) and two-thirds liberal (same). It was the state next to his home state. It was a state he should have won big - and a state he did win big.

South Carolina was the same for Hillary Clinton.

According to preliminary exit poll data reported by CNN, the electorate in yesterday's primary voting was heavily African-American - even more so than in the 2008 election that gave Barack Obama a 2-to-1 victory. Exit polls suggest that black voters supported Clinton by a 4-to-1 margin.

In 2008, 78 per cent of black voters supported Barack Obama and 19 per cent supported Clinton. Four in five voters said race relations were important in deciding their vote - and about 70 per cent of those picked Clinton.

It was also a more moderate electorate than the first three states. About seven in 10 moderate voters supported Clinton. Seven in 10 voters also want to continue Obama's policies, versus moving in a more liberal direction. Guess what! They supported Clinton - who has made a point of bear-hugging Obama - at a 4-to-1 margin, too.

Those 65 and over also backed Clinton by a 4-to-1 margin.

South Carolina was intended to be one of the bricks in Hillary Clinton's "firewall" against a Bernie Sanders surge. That was because of her strong support from black voters.

An interesting rift has emerged, though, between young black and Hispanic voters and older ones. The former appear more likely to back Sanders, the latter Clinton.

The question then, was if Sanders could make headway with non-white voters. It seems not.

Last October, Sanders' strategist suggested that the candidate only needed to win 30 per cent of the black vote in the state to win the state. He appears to have barely hit half of that.

This is a huge problem for Sanders because a number of large upcoming states also have large non-white populations.

If Sanders did worse than expected here, why would he do better than expected there?

It's worth remembering that, in the busy schedule over the next few weeks, Sanders won't have been able to spend much time on the ground, certainly not spending as much time as he did in Iowa or New Hampshire.

And the delegates will be allocated proportionately, meaning that if Clinton runs up the margins, she runs up the delegates, too.