Pollster says Trump's approval rating in 2020 will be impacted by Dem nominee

Pollster Mike Greenfield told Hill.TV on Wednesday that President TrumpDonald John TrumpForget the spin: Five unrefuted Mueller Report revelations Lara Trump: Merkel admitting migrants 'one of the worst things that ever happened to Germany' Financial satisfaction hits record high: survey MORE's approval rating going into 2020 will likely depend on the popularity of his future Democratic opponent. 

"It's going to matter who the Democrat is," Greenfield, the CEO and co-founder of Change Research, told host Jamal Simmons on "What America's Thinking." 

"We're seeing in early polling that [Joe] Biden does a little bit better than other candidates, and obviously that still has to be fleshed out," he continued. 

"People don't know a lot of the other candidates, but it does matter who the Democrat is," he said. 

A new Hill-HarrisX survey, released on Wednesday, showed the president's approval at 46 percent. 

An Emerson College survey, released last month, showed former Vice President Biden beating Trump in a hypothetical race by 10 points. Biden is expected to announce his run later this month.

The survey also showed Sen. Kamala HarrisKamala Devi HarrisThe symbol of 'Wakanda' and black political vision Seven big decisions facing Biden in 2020 primary Sanders dominates, Buttigieg surges in 2020 social media battle MORE (D-Calif.) beating Trump by four points, while Sens. Elizabeth Warren (D-Mass.) and Bernie Sanders (I-Vt.) each edge Trump by 2 points. 

— Julia Manchester