POWER RANKINGS: Here's who has the best chance at being our next president

REUTERS/Mike Carlson

After Iowa and New Hampshire, it's on to South Carolina and Nevada.

Republican voters will head to the polls in South Carolina on Saturday, while Democrats in Nevada will caucus for their preferred candidate.

On both sides, the insurgent candidates are trying to sustain huge streaks of momentum off impressive wins in the New Hampshire primaries.

Republican candidate Donald Trump and Democratic hopeful Bernie Sanders each notched a double-digit victory in New Hampshire after a narrow loss in the first-in-the-nation Iowa caucuses.

Trump is now looking for a defining victory in the Palmetto State, while Sanders is trying to prove he can challenge Democratic frontrunner Hillary Clinton in a state whose electorate is more favorable to the former secretary of state.

With all that in mind, we take another look at who has the best chance of making it to the White House to succeed President Barack Obama.

Our rankings are based on the Real Clear Politics averages of national polls and those in the states of South Carolina and Nevada. We also factored in the candidates' delegate count and their finishes in Iowa and New Hampshire, as well their momentum (or lack thereof) over the past few weeks.

Since New Hampshire, two more Republican candidates have dropped out of the race: former Hewlett-Packard CEO Carly Fiorina and Gov. Chris Christie of New Jersey.

Here's a look at where all the candidates stand.

All poll results as of Thursday.

8. Ben Carson, Republican, retired neurosurgeon

REUTERS/Carlo Allegri

Carson has continued to slide after a stunning rise that peaked in October, when he became the first Republican since July to overtake Donald Trump for first place in a national poll.

Like Trump, Carson is a Washington outsider who has shown that he can appeal to a broader electorate. And like Trump, even some of the more controversial things to come out of Carson's mouth have seemed to help his fund-raising and poll numbers.

But his time in the intense spotlight looks as if it has taken its toll, as scrutiny has pervaded over his potential as commander-in-chief. His campaign, thrown into disaster in late December with the resignation of top aides, continues to hit speed bumps.

His national and state poll numbers continue to plunge, and it's unclear where he can be competitive from here on out.

National polling average among Republican voters: 6.6% (5th)
South Carolina: 6.8% (6th)
Nevada: 6% (5th)

DELEGATES: 3
STOCK: Falling
Last month: 9

7. Jeb Bush, Republican, former Florida governor

Thomson Reuters

Bush, once viewed as the clear frontrunner, has seen Trump sap the momentum Bush had built after his official campaign announcement in June.

His poll numbers have slumped across the board — his 17% national average in July has dipped almost 12 points over the past seven months, even as other candidates have dropped out.

Bush finished in a strong fourth place in New Hampshire, ahead of Rubio. He has brought on former President George W. Bush, his brother, to campaign for him in South Carolina, where observers say he needs another strong finish to build momentum as a possible establishment alternative to Trump.

Bush has showed, too, that he is a dynamic fund-raiser. And he retains significant resources, especially in the super PAC allied with his campaign.

National polling average among Republican voters: 5.4% (6th)
South Carolina: 10.4% (4th)
Nevada: 3% (6th)

DELEGATES: 4
STOCK: Neutral
Last month: 6

6. John Kasich, Republican, Ohio governor

Thomson Reuters

Kasich finished an impressive second in New Hampshire, a feat that has proved to be a serious boon to his presidential ambitions. But South Carolina and subsequent states present potential stumbling blocks.

Those who talk up Kasich say he is a successful governor of a swing state with a record to point to and clear bipartisan appeal. He also has a plethora of experience from nearly two decades in Congress, including foreign-policy areas and his time as chair of the US House budget committee.

But that same bipartisan brand could hurt Kasich with the GOP base beyond New Hampshire. He is to the left of most GOP candidates on immigration reform, and he expanded the federal Medicaid program under the Affordable Care Act — two issues that could doom him with hard-line conservatives.

National polling average among Republican voters: 8.6% (4th)
South Carolina: 9.6% (5th)
Nevada: 7% (4th)

DELEGATES: 5
STOCK: Rising
Last month: 7

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