Hillary Clinton holding leads in Nevada and South Carolina, CNN poll shows

Hillary Clinton is holding a strong lead among Democratic voters in the early voting states of Nevada and South Carolina, according to a new CNN-ORC poll.

Democrats who say they are likely to attend Nevada's Feb. 20 caucus prefer Clinton over Vermont Sen. Bernie Sanders, 50% to 34%. Vice President Biden, who is still considering whether he will run, was favored by 12%, according to CNN.

In South Carolina, where Democrats vote Feb. 27, Clinton leads Biden 49% to 24%, with Sanders running third in at 18%.

The results show that despite weaker numbers in New Hampshire and Iowa, Clinton still has a sizable advantage in two of the four early voting states. And her lead only grows if Biden opts out, the poll showed.

Without Biden on the ballot, Clinton's lead over Sanders in South Carolina becomes 70% to 20%, with former Maryland governor Martin O'Malley at 3%. In Nevada, it becomes 58%-36%, Clinton over Sanders.

CNN described the poll results as a firewall for Clinton, should she fail to win New Hampshire or Iowa.