WASHINGTON -- Businessman Donald Trump leads the Republican field in South Carolina, according to a poll that also has former U.S. Secretary of State Hillary Clinton ahead on the Democratic side.

The CNN/ORC International poll released Tuesday gave Trump 38 percent, virtually unchanged from the 36 percent he received in October. Texas Sen. Ted Cruz was second with 22 percent, up from 5 percent in the earlier survey. They were followed by Florida Sen. Marco Rubio, 14 percent; former Florida Gov. Jeb Bush, 10 percent; retired neurosurgeon Ben Carson, 6 percent; and Ohio Gov. John Kasich, 4 percent.

Clinton led Vermont Sen. Bernie Sanders, 56 percent to 38 percent. She was ahead of Sanders in October, 49 percent to 18 percent.

Nationally, Trump led a Quinnipiac University poll released Wednesday with 39 percent, followed by Rubio with 19 percent and Cruz with 18 percent. In a poll taken Feb. 2-4, before the New Hampshire primary, Trump had 31 percent, Cruz 22 percent and Rubio 19 percent. Among Democrats, Clinton was ahead of Sanders, 44 percent to 42 percent, unchanged from the earlier survey and within the poll's margin of error.

"Like a freight train barreling through signals with his horn on full blast, Trump heads down the track towards a possible nomination," said Tim Malloy, assistant director of the Quinnipiac poll.

South Carolina Republicans vote this Saturday, the next stop on the road to the GOP presidential nomination, and Democrats vote Feb. 27 after the Nevada caucuses.

Here are five takeaways from the South Carolinapoll:

1. Republicans say Trump can win.

More than half of likely Republican primary voters, 53 percent, said Trump, the winner of the New Hampshire primary, was their strongest candidate against the Democrats this fall, compared with 19 percent who chose Cruz and 16 percent who picked Rubio.

2. GOP voters agree with Trump on the issues.

By 60 percent to 16 percent, likely GOP voters said Trump rather than Cruz was most likely to change the way Washington works.

Besides that, 58 percent said Trump was best able to handle the economy, 53 percent said immigration, 44 percent said the Islamic State.

3. Here's one reason why Trump and Cruz went at it on Saturday.

Cruz, the winner of the Iowa caucuses and third-place finisher in New Hampshire, has emerged as Trump's strongest challenger.

In the ninth GOP presidential debate last Saturday, Cruz called Trump "an amazing entertainer," whose policies have been "very, very liberal." Trump called Cruz a "nasty guy."

Cruz still has plenty of room to grow. Just 49 percent of the likely Republican electorate definitely has decided on a candidate, and 31 percent has yet to decide. The remainder is leaning toward someone.

In a state where 65 percent of the 2012 Republican primary voters identified as Christian conservatives in exit polls, Trump barely led Cruz, 27 percent to 26 percent, on the question of which candidate most represented their values, well within the margin of error.

While Trump's support has remained static, Cruz has been on the upswing. In October, 25 percent said Trump most represented their values and 19 percent picked Carson. Cruz was at 6 percent.

4. Cruz and Rubio are identical on social issues, but GOP voters favor the former.

More than one-quarter of the likely GOP primary voters, 28 percent, said Cruz was best able to deal with social issues such as abortion and same-sex marriage. Trump was second with 21 percent.

Just 15 percent chose Rubio, who, like Cruz, does not believe in exceptions to opposing abortion in cases when women are raped, and that the next president should back legislation allowing individuals and businesses to cite their religious beliefs and deny service to same-sex couples.

5. South Carolina Democrats prefer Clinton on every issue.

Likely Democratic primary voters said Clinton would do the best job handling health care, the economy, gun rights, race relations and foreign policy. They said Clinton more than Sanders represented their values by 57 percent to 41 percent, and two-thirds of respondents, 67 percent, said Clinton had the best chance of winning the general election. Just 29 percent chose Sanders.

The CNN surveys were taken Feb. 10-15, after New Hampshire. The margin of error for the 404 likely Republican primary voters was 5 percentage points and for the 280 likely Democratic primary voters was 6 percentage points.

Quinnipiac's polls also were conducted Feb. 10-15. The survey of 602 Republicans had a margin in of error of 4 percentage points and of 563 Democrats had a margin of error of 4.1 percentage points.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant. Find NJ.com Politics on Facebook