The former secretary of state has 44% of voters' support while the Vermont senator has 42%. And 11% of voters are undecided, unchanged from a February 5 national survey
from Quinnipiac. Clinton was ahead of Sanders by two percentage points in the February 5 survey as well.
"Sen. Bernie Sanders and Secretary Hillary Clinton are neck and neck. But while Bernie has the trust, Hillary has the experience. Two different measurements of two dissimilar candidates," said Tim Malloy, assistant director of the Quinnipiac University Poll.
Other national polls haven't shown the Democratic race so close, though Quinnipiac is one of the few major polling outlet to release national results since voting began this month.
The Democratic gender gap is shrinking. Female participants in the survey back Clinton over Sanders 47% to 41%, while men supported Sanders 44% to 40%.
Clinton has a good chance of winning in November, according to 83% of Democrats compared to 69% who believe Sanders has a good chance.
Trump now has a 2-1 lead among Republican voters nationwide. At 39%, the Republican front-runner is leading Florida Sen. Marco Rubio by 20 points.
"Like a freight train barreling through signals with his horn on full blast, Trump heads down the track towards a possible nomination," Malloy said.
Rubio has 19% and Texas Sen. Ted Cruz is in third with 18%. Ohio Gov. John Kasich has 6% and former Florida Gov. Jeb Bush and Dr. Ben Carson are both at 4% each. Undecided voters are at 9%.
Trump has a good chance of winning in November, according to 77% of Republican voters, while 61% say Rubio has a good chance of winning and 60% say Cruz has a good chance.
The poll was conducted from February 10-15 by live interviewers on land lines and cell phones. The survey included 1,342 registered voters nationwide with a margin of error of +/- 2.7 percentage points. It included 602 Republicans with a margin of error of +/- 4 percentage points and 563 Democrats with a margin of error of +/- 4.1 percentage points.