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Joe Biden hasn’t yet announced his plans for a 2016 White House bid, but a new poll shows that he would enter the race as the most popular presidential candidate if he chose to toss his hat into the ring.

According to a new NBC News/Wall Street Journal poll, 40 percent of Americans have a positive impression of Biden, while 28 percent have a negative impression (+12).

That’s compared to fellow Democrats Bernie Sanders (+10) and Hillary Clinton (-8), and to top-tier GOP candidates Ben Carson (+8), Carly Fiorina (+7) and Donald Trump (-33).

Biden would also out-perform Clinton in hypothetical head-to-head general election matchups against top Republican presidential hopefuls.

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If the 2016 election was held today, voters overall say they’d back Clinton over Trump by 10 points (49 percent to 39 percent), but the former secretary of state would be statistically tied with Fiorina (45 percent for Fiorina, compared to 44 percent for Clinton), Carson (46 percent for Carson, compared to 45 percent for Clinton), and former Florida governor Jeb Bush (44 percent for Bush, compared to 45 percent for Clinton).

But Biden would fare better, besting Bush by eight points (48 percent to 40 percent), Fiorina by six points (47 percent to 41 percent), Carson by eight points (49 percent to 41 percent), and Trump by 19 points (56 percent to 35 percent).

In a hypothetical matchup with Donald Trump, Sanders would also handily defeat the real estate mogul, getting 52 percent of the general election vote compared to Trump’s 36 percent.

Part of Biden’s current popularity is almost certainly attributable to the fact that he’s not officially in the 2016 race. Most of the media coverage of the vice president’s potential run has centered around his decision-making about a campaign and the outpouring of sympathy for his family after the tragic death of his son, Beau. None of his potential rivals have aggressively attacked his record, including past gaffes and previously held policy positions that might now be anathema to the Democratic Party’s progressives.

“History has shown that the public has a much harsher filter when people become candidates,” says Republican pollster Bill McInturff, who conducted the poll along with Democratic pollster Peter Hart.

And Biden still trails in the Democratic primary, capturing the support of 17 percent of Democratic primary voters, compared to 35 percent for Sanders and 42 percent for Clinton.

If Biden chooses not to pursue a run for president, Clinton’s lead with Democrats would jump. Fifty-three percent of Democratic primary voters say they’d support Clinton without Biden in the race, compared to 38 percent who would back Sanders.

Clinton’s overall favorability rating now stands at 39 percent positive, 47 percent negative. When Clinton announced her presidential candidacy in April of this year, that rating was 42 percent positive, 42 percent negative.

The NBC/WSJ poll was conducted Sept. 20-24 of 1,000 adults (including nearly 400 reached by cell phone), and it has an overall margin of error of plus-minus 3.1 percentage points.