This poll has a MOE of +/- 2%
"The interviews were collected from July 8-14, 2019 and have a margin of error of +/- 2%. The “Early Primary State Voters” demographic consists of 685 voters in Iowa, New Hampshire, Nevada, and South Carolina."
"Biden stabilizes after post-debate slide, has 32% of the vote share. However, his net favorability has dropped by 18 points since January, now stands at +51. "
The latest nationwide Democratic primary tracking data
Biden: 32% (+1) +13
Sanders: 19%
Warren: 14% (+1)
Harris: 13% (-1)
Buttigieg: 5% (-1)
O'Rourke: 3%
Booker: 2%
Yang: 2%
Then the early states
Biden 33% +11
Sanders 22%
Warren 11%
Harris 11%
Buttigieg 5%
Booker 4%