CNN poll: Bernie Sanders surges to join Biden atop Democratic presidential pack

The poll marks the first time Biden has not held a solo lead in CNN's national polling on the race.

Overall, 27% of registered voters who are Democrats or Democratic-leaning independents back Sanders, while 24% favor Biden. The margin between the two is within the poll's margin of sampling error, meaning there is no clear leader in this poll. Both, however, are significantly ahead of the rest of the field, including Massachusetts Sen. Elizabeth Warren at 14% and former South Bend, Indiana, Mayor Pete Buttigieg at 11%. Former New York Mayor Michael Bloomberg lands at 5% in the poll, while Minnesota Sen. Amy Klobuchar and businessman Andrew Yang each hold 4% support. Businessman Tom Steyer has 2%. No other candidate reaches 1% support.

Sanders has gained 7 points since the last CNN poll on the race in December. Since that survey, the Vermont senator has also made gains in early-state polling, including CNN's survey with the Des Moines Register in Iowa, where the first caucuses of the cycle will be held in less than two weeks.

Sanders has made gains nearly across the board, clearly pulling away from Warren among liberals (33% back Sanders, while 19% support Warren in the new poll), a group where the two had been running closely through much of the fall. Sanders has also pulled about even with Biden among voters of color (30% for Sanders, 27% for Biden).

As the campaign has taken a more negative turn, Democratic voters remain about as enthusiastic about a potential Sanders nomination as they were earlier this fall (38% say they would be enthusiastic should he win the nomination, on par with the 39% who felt that way in October), while his chief rivals have seen enthusiasm waning (enthusiasm for a Biden nomination has dipped 9 points to 34%; for Warren, it's fallen 12 points to 29%).

Sanders is also most often seen as the candidate who agrees with voters on the issues that matter most to them (30% say that's Sanders compared with 20% for Biden, 15% for Warren and 10% for Buttigieg), and as the candidate who best understands the problems facing people like you (29% name Sanders as best on that measure, 18% Biden, 17% Warren and 9% Buttigieg).

Electability and unity

Biden remains the candidate a plurality of Democrats say has the best chance to defeat Trump (45% say so of Biden, compared with 24% for Sanders, 8% for Warren, 7% for Bloomberg and 4% for Buttigieg), but Sanders has made gains here too, rising from 16% on this question in December to 24% now.

The share of Democrats who say nominating a candidate who can defeat Trump is more important than choosing one who agrees with them on the issues has rebounded to 57%, according to the poll. Sanders has made gains as the preferred choice of potential Democratic voters who prioritize defeating the president as well: In December, 14% in this group backed him; now, 20% do so. That gain appears to have come at Warren's expense.Her share within this group dipped from 21% to 14%. Biden has held about even among this group, from 28% in December to 30% now.

There's a similar dynamic between Sanders and Biden at play over uniting the country, with 39% saying Biden has the best shot at that while 22% name Sanders, but with Sanders gaining ground since December (14% named him in the December poll).

Fewer think Sanders has the best shot to unite the Democratic Party, however, as just 16% name him, compared with 41% naming Biden.

The general election

Looking ahead to the general election, the poll finds Biden, Bloomberg, Sanders and Warren each holding significant leads over Donald Trump, with the support of 50% or more of registered voters nationwide. Buttigieg tops Trump with 49% to the president's 45%, and Klobuchar and Trump are near even, 48% for Klobuchar to 45% for Trump.

Enthusiasm for voting in the 2020 election appears to have dipped a bit from its December high point in the new poll, with the numbers declining by double digits among both Democrats and Republicans. Enthusiasm for voting has bounced a bit throughout CNN's polling this past fall, but has consistently remained at a higher level than is typical even for the fall of an election year.

The drop in deep enthusiasm among Democrats was sharper than the one among Republicans, and the current poll finds the most enthusiastic voters leaning in Trump's direction in just about every matchup.

The poll included an oversample of those living in 15 battleground states, defined as those where the race between Clinton and Trump in 2016 was decided by 8 points or fewer. In those states, the poll finds consistently tight races regardless of the nominees, with Democrats ranging from 46% to 49% support and Trump from 47% to 50%. In none of the six tested matchups does either candidate hold a significant advantage.

Asked whether a woman can win the US presidency, a whopping 84% of voters say yes, but there is a notable gender divide here. While only 9% of men say a women could not win the U.S. presidency, that figure about doubles among women, 20% of whom say no, a woman cannot win the presidency. That figure stands at roughly 20% among women regardless of age, party, education level or race.

The poll finds there continues to be a chasm between Democratic-leaning and Republican-leaning voters over the most important issues in their votes for president.

For Democrats and Democratic-leaning independents, health care (55% extremely important) and climate change (50%) dominate, with gun policy third (37%) while the economy (32%), immigration (32%) and foreign policy (31%) lag behind. For Republicans and Republican-leaners, just 27% cite health care as extremely important and only 8% consider climate change that important. At the top of their list is the economy (49% extremely important), followed by gun policy (41%) and immigration (36%).

The CNN Poll was conducted by SSRS January 16 through 19 among a random national sample of 1,156 adults reached on landlines or cellphones by a live interviewer. Results for the full sample have a margin of sampling error of plus or minus 3.4 percentage points. For the sample of 500 registered voters who are Democrats or Democratic-leaning independents, it is 5.3 percentage points.