Vice President Joe Biden trails Hillary Clinton for the Democratic nomination, yet he looks more electable than the former secretary of state against top Republicans. 

As Democrats prepare for their first debate Tuesday evening, the latest Fox News national poll finds little movement in the primary. Clinton remains the front-runner among Democratic primary voters (45 percent), with Bernie Sanders (25 percent) and Biden (19 percent) behind her by about 20 percentage points. That's almost identical to where things stood three weeks ago. 

Lincoln Chafee, Larry Lessig, Martin O'Malley, and Jim Webb each receive 1 percent or less. 

Biden, who has yet to announce his candidacy, was invited to participate in the debate if he were to make it official; Lessig was not invited. 

CLICK HERE TO READ THE POLL RESULTS 

In hypothetical 2016 matchups with top-tier Republicans, Clinton trails all the Republicans tested. She trails Ben Carson by 11 points and Donald Trump by 5 points. Jeb Bush has a 4-point edge over Clinton, while Carly Fiorina is up by 3 points. 

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Biden fares better. He leads Trump by 13 points and tops Bush by 5 points. Biden is preferred over both Fiorina and Carson by 4 points. And Biden narrowly bests Marco Rubio by 1 point. 

Though Clinton still dominates the Democratic primary race, the new poll confirms a significant decline in her support since summer. In June, her lead over Sanders was double what it is today (61 percent Clinton vs. 15 percent Sanders). And instead of trailing Trump by 5 points, she topped him by 17 points. Clinton was also up by 6 points over Fiorina then, while she's down by 3 now. 

Contrary to the chatter from some pundits, party "trumps" gender. Women are more inclined to back the Democrat over Fiorina whether it is Clinton (+7 points) or Biden (+12 points). Men are more likely to back Fiorina over Clinton by 14 points, yet Fiorina's edge narrows to 5 points over Biden. 

Pollpourri 

How would the 2016 contest look if Biden were to pick Massachusetts Sen. Elizabeth Warren as his running mate?  Voters prefer a Biden-Warren ticket over both a Trump-Fiorina ticket (48-42 percent) and a Bush-Rubio combo (45-43 percent). 

The Fox News poll is based on landline and cell phone interviews with 1,004 randomly chosen registered voters nationwide and was conducted under the joint direction of Anderson Robbins Research (D) and Shaw & Company Research (R) from October 10-12, 2015. The poll has a margin of sampling error of plus or minus 3 percentage points for all registered voters, 5 points for Democratic primary voters and 4 points for the head-to-head match-ups.