Considering that Trump had a positive approval rate in GA last year according to exit polls, it's hard to see how he is it underwater now.
No, it isn't. Things can change quite a bit in a whole year. Trump continues to turn off suburban voters, while it's doubtful that he's gaining enough elsewhere to make up for those losses.
He isn't really "turning them off." They're just idiotic dimwits who are manipulated like string puppets by the media.
There actually is no evidence that Trump is more unpopular in the suburbs relative to 2016. Arguably he can do better in 2020 relative to 2016 in many of those areas.
In 2018 many of the districts that flipped were ones that Hillary won! The ones that Trump won that flipped were arguably more so due to incumbents being lazy, differential turnout, that kind of thing - not that >50% in those districts now will plan to vote against Trump. For instance OK-05, SC-01, NY-19, NY-22, NM-02, and others should still vote for Trump in 2020.
"Suburbs are abandoning Trump" is a meme. The reality is more along the lines of "areas that Romney won, which Hillary later won, are going to be troublesome for Trump in 2020" -> but note that Trump can still do better in some of those areas than he did in 2016!
