According to a Zogby Survey of 576 likely democratic voters, conducted online from 8/6/18 to 8/8/18, with a margin of error of +/-4.1 percentage points, Joe Biden has expanded his lead over his closest rival, Bernie Sanders, for the potential democratic nomination for president in 2020.

Overall, former Vice President Joe Biden has a comfortable lead (27%) over the independent Senator from Vermont, Bernie Sanders (16%), while nearly a third (31%) of democratic primary voters are not sure who they would vote for.

Rounding out the list of potential contenders are Senators Elizabeth Warren-MA (7%), Kamala Harris-CA (5%), and Cory Booker-NJ (4%). At the bottom of the list are Andrew Cuomo (3%), Kirsten Gillibrand (2%), Sherrod Brown (2%), Eric Holder (2%), John Delaney (1%), Terry McAuliffe (1%), and Deval Patrick (1%).

This time around we left out media mogul Oprah Winfrey, who has given every indication she is not seeking the democratic nomination for president in 2020. It appears Biden has picked up some of her support since our last poll, which showed a tighter contest between Joe Biden and Bernie Sanders when Winfrey was among the choices.

In a seemingly consistent pattern since our polling began last year, Sanders leads among younger voters age 18-24 (Sanders leads 24% to 20%) and age 18-29 (Sanders leads 22% to 15%), but Biden is narrowing Sanders' lead among Millennials and Generation Z voters. Among older Millennials age 25-34, Biden leads Sanders 19% to 16%. Still, pluralities of likely democratic voters age 18-24 (45%) and 18-29 (38%) are not sure which candidate they would support. Senator Elizabeth Warren (MA) did better among voters age 25-34, receiving 10% of their support. Joe Biden also does well with both men (Biden leads Sanders 27% to 15%) and women voters (Biden leads Sanders 27% to 18%).

Biden is clearly the favorite among registered democrats. He expands his lead over Sanders to 33% to 18%, while Senators Kamala Harris (7%) and Elizabeth Warren (5%) are the next closest candidates.

Which candidate independent likely voters will support is not clear, as three candidates do very well with this group. Sanders (15%), Biden (16%) and Warren (10%) each receive double digit support among independent likely voters who say they will vote in the democratic primary. The next closest potential candidates were Cory Booker and Deval Patrick, each receiving 4% support.

Biden did best among white (Biden leads Sanders 24% to 14%) and African American voters (Biden leads Sanders 37% to 16%), while Sanders did better among Hispanics (Sanders leads Biden 23% to 20%). Kamala Harris comes in third at 9% among African Americans, and both Elizabeth Warren and Kamala Harris finish third among Hispanics, both receiving 7% of their support.

Where likely voters lived was also a factor in which democratic candidate they supported; Biden did well among large city voters (Biden leads Sanders 28% to 17%), suburban voters (Biden leads Sanders 26% to 10%) and rural voters (Biden leads Sanders 36% to 20%). The former Vice President also leads among union voters (Biden leads Sanders 26% to 13%), weekly Walmart shoppers (Biden leads Sanders 26% to 16%), weekly Amazon shoppers (Biden leads Sanders 32% to 15%) and NASCAR fans (Biden leads Sanders 26% to 12%). Sanders beats Biden among small city voters (Sanders leads Biden 21% to 20%), but Biden seems to be the choice among democratic voters who are enjoying the benefits of a good economy; we asked respondents if their "finances were better off than four years ago" (Biden leads Sanders 23% to 13%), and voters who are most vulnerable-we asked respondents if they had "gone without food for 24hrs" (Biden leads Sanders 19% to 10%), were "afraid of losing a job" (Biden leads Sanders 27% to 13%), and if they "have lost a job" (Biden leads Sanders 24% to 10%).

Three Takeaways

• When we leave out media titan Oprah Winfrey from the list of potential democratic candidates, Biden retains a comfortable lead, especially over his closest competitor, Senator Bernie Sanders (I-VT).
• Biden is closing in on more support from younger voters, and does well with swing voters such as independents, small city voters and consumer voting blocs we regularly track-Walmart shoppers, Amazon Shoppers and NASCAR fans.
• Elizabeth Warren is starting to separate herself in third place. She receives double digit support (10% or slightly more) with likely voters who are independents, NASCAR fans, rural, age 25-34, earn $35-50k annually, and have gone without food for 24hrs.