The chart above uses information from a new Public Policy Polling survey -- done between January 19th and 21st of a national sample of 760 registered voters, with a 3.6 point margin of error.
It shows the current weakness of Donald Trump. If the 2020 election was held now, all the the top Democratic contenders would beat him -- Joe Biden by 12 points, Bernie Sanders by 10 points, Kamala Harris by 7 points, Elizabeth Warren by 6 points, Beto O'Rourke by 6 points, Cory Booker by 5 points, and Kirsten Gillibrand by 5 points. All of those leads exceed the poll's margin of error.
There's still about 22 months before the 2020 election, and much could change. But if Trump wants to get re-elected, he has a lot of work to do -- and he needs to stop trying to appeal just to his base, and do something to broaden his appeal.
NOTE -- The survey also said Chuck Schumer would beat Trump by 5 points, and Nancy Pelosi would beat him by 3 points.