Democratic presidential front-runner Hillary Clinton continues to slip in the national polls, only leading her closest challenger, Sen. Bernie Sanders, I-Vt., by 10 percent. At the same time, Clinton no longer beats Republican candidates in hypothetical matchups, according to a CNN poll released late Thursday.

Clinton now has 37 percent support among Democratic and Democratic-leaning voters, down 10 points since August, while Sanders is at 27 percent, the same as in August. Vice President Joe Biden, who has not yet decided whether he will run for president, is in third place with 20 percent, up 6 points from last month.

Former Maryland Gov. Martin O'Malley took 3 percent, former Virginia Sen. Jim Webb got 2 percent and former Rhode Island Gov. Lincoln Chaffee is at less than 1 percent.

Clinton is also now trailing a number of Republican candidates in hypothetical general election matchups. Retired neurosurgeon Ben Carson beat Clinton by a significant margin, 51-46 percent, while former Florida Gov. Jeb Bush came out on top too, 49-47 percent. Billionaire real estate mogul and GOP front-runner Donald Trump tied Clinton with 48 percent each.

Clinton's controversial use of a private email system during her tenure as secretary of state, which is currently being investigated by the FBI, has significantly impacted voters' perception of her, and a majority of voters now view her as an untrustworthy liar, according to a recent Quinnipiac University poll.

While women were once one of Clinton's most supportive demographics, that advantage has also disappeared in matchups against Carson and Bush, while she still carries women by a large margin when facing Trump, according to CNN's findings.

In other recent polls in the early primary states of New Hampshire and Iowa, Sanders has already taken the lead over Clinton, as HNGN previously reported.

CNN's poll was conducted among 1,012 Americans between Sept. 4-8 and has a margin of error of plus or minus 3 percentage points.