Story highlights Hillary Clinton leads Bernie Sanders nationally, 48% to 42%, in CNN's Poll of Polls

In South Carolina, Clinton's lead is larger, at 56% to Sanders' 32%

Washington (CNN) Hillary Clinton continues to lead nationally in the Democratic primary fight, but Bernie Sanders has narrowed the gap to 6 percentage points, according to a new CNN Poll of Polls.

Clinton is up 48% to the Vermont senator's 42% -- a tighter race than the 53% to 36% that the previous Poll of Polls found just before the Iowa caucuses.

In South Carolina, though, Clinton has a much bigger lead, with 56% support to Sanders' 32% -- reflecting Clinton's strength among African-Americans who make up a huge portion of the party's electorate there.

The closer picture of the race comes just two days before Nevada's caucuses, where Clinton's organizational strength and "firewall" of minority voters faces its first true test from Sanders.

After Clinton's narrow win in Iowa and Sanders' blowout victory in New Hampshire, the Democratic race is now sure to extend into March, when 56% of the party's delegates will be awarded and 28 states will vote.

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