My guess is that,

[MoonRiver]

somebody smarter than Dim Don, but not very well educated either, is producing his idiotic tweets. The morons clearly think they are waging a war against democracy, regardless of party affiliation. Since he (they) are also attacking Repubs, channeling Breitbart, I do not see this ending well for Idiot-in-Chief & Co. 2018 will give us the answer.

[Tommy_Carcetti]

1. I think it's a mix.

Some are farmed off to staff, but some I think he legitimately writes, simply because they match his verbal speaking habits.

[MoonRiver]

2. Could be. There are lots of spelling and grammatical errors in his tweets.

But the fool may only trust other idiots to write and edit! After all, he knows what level they are on. Smarter, better educated people, not so much.

[dalton99a]

3. I think they're mostly his

if you look at the archive and do a random check

[Tommy_Carcetti]

4. Remember, he's a guy who years ago didn't trust anyone else to be his publicist.

So he invented "John Barron" and "John Miller".

He's a narcissist and will do anything to protect what he sees is his own image, and rejects anyone else's attempt to shape it for him.

That's why anyone who attempts to "reform" Trump into President Eliza Doolittle will inevitably fail.

[dalton99a]

5. Yep, his paranoia is well documented

[MoonRiver]

6. He's a massively twisted person.