Democratic presidential candidate Joe Biden and his wife, Jill, wave to the crowd during his 2020 campaign kickoff rally at the Eakins Oval in Philadelphia, Pa., on Saturday, May 18, 2019.

President Donald Trump lags behind all the top Democratic 2020 contenders with his job approval rating under water at 45%, according to a new NBC News/Wall Street Journal poll.

Former Vice President Joe Biden currently leads Trump by 9 points, the widest margin among the top four Democratic contenders. That's well outside the poll's margin of error of 3.5 percentage points.

Biden's large lead over Trump is largely thanks to his performance among potential tossup voters. He has a 6-point advantage among suburbanites and a 4-point lead among independents, according to NBC.

Sen. Bernie Sanders leads Trump by 7 points and Sen. Elizabeth Warren has a 5-point advantage over the president. Sen. Kamala Harris, on the other hand, is locked in a dead heat with Trump.

She leads the president by just a single percentage point -- a tossup -- despite having risen to third place in the field of Democratic candidates among those voters who intend to cast a ballot in the primary.



Harris polled among the top tier candidates in a NBC News/Wall Street Journal poll earlier this month after she confronted Biden in the first Democratic debate for comments he made about working with segregationist senators.



Though Trump does not lead any of the top Democratic candidates in a hypothetical 2020 matchup, there are potentially troubling signs for three of the top contenders. Trump is either even with or has a slight advantage over Sanders, Warren and Harris among suburbanites and independents.



The NBC/WSJ poll surveyed 800 registered voters July 7-9. More than half of those voters were reached by cell phone. The poll has an overall margin of error of plus or minus 3.5 percentage points.

