Yet another presidential poll shows Republican candidate Donald Trump extending his lead over the rest of the field, garnering more support than the next three candidates combined.

In the latest CNN/ORC poll, Trump comes in with 38 percent support, up three points from late November and 21 points ahead of the next candidate, Texas Sen. Ted Cruz, who is at 18 percent, up two percentage points.

Retired neurosurgeon Ben Carson and Florida Sen. Marco Rubio are now tied at 10 percent, with Carson dropping four points and Rubio two points. New Jersey Gov. Chris Christie rose one point to 5 percent in the latest poll. No other candidate got more than 5 percent support, including former Florida Gov. Jeb Bush, who is at 3 percent.

Most respondents, 57 percent, said they think Trump is best equipped to handle the economy, while all other Republican contenders are in single digits. Fifty-five percent believe the real estate mogul would take care of the country's illegal immigration problem better than any other candidate, followed by Cruz at 15 percent and Rubio at 10 percent. A large plurality, 47 percent, also said Trump would handle the Islamic State best, while 21 percent think Cruz would do a better job.

CBS News notes that Trump typically struggles to gain support from Republican college graduates, however, the latest poll shows 27 percent of GOP voters with degrees now support him, up from 18 percent in the last poll. Forty-six percent of those without degrees support Trump, the same number as in the previous poll.

Cruz has the highest favorability rating of any GOP candidates, at 45 points, up 22 points since September. More respondents also said Cruz has the best experience to be president, 62 percent, compared to Trump's 57 percent.

The telephone poll was conducted Dec. 17-21 among 1,018 adults and has a margin of sampling error of plus or minus three percentage points for the full sample. Among the 438 registered Republicans or right-leaning independents, the margin of error is plus or minus 4.5 percentage points.