Hillary Clinton's lead in the Democratic presidential primary race has grown -- and if Vice President Joe Biden decides to stay out of the race, her numbers would rise even higher, a new CNN/ORC poll shows.
Clinton is backed by 42% of Democratic primary voters nationally, compared to 24% for Vermont Sen. Bernie Sanders, 22% for Biden and 1% for former Maryland Gov. Martin O'Malley.
That's a marked improvement over an early September CNN/ORC poll that found Clinton leading Sanders, 37% to 27%, with Biden at 20%.
And Biden's support comes almost entirely from Clinton's camp. Without the vice president in the race, Clinton's numbers climb by 15 percentage points, while Sanders' increase by only 4 points -- giving Clinton a nearly 2-to-1 lead at 57% to 28%, with O'Malley moving up to 2%.
While Clinton has led national polls, she has been found trailing in New Hampshire and at times in Iowa -- two key early voting states. And her downward trend nationally -- amid questions about her use of a private email server during her tenure as President Barack Obama's secretary of state -- has fueled speculation of a late Biden entry, and provided the vice president with an opening even as he grieves the death of his son Beau Biden.
Biden is still mulling a potential bid.
The poll surveyed 392 Democrats and independents who lean toward the Democratic Party from September 17-19 and has a margin of error of plus or minus 5 points.