I believe Trump's inflammatory twitters are for two reasons.

[Cosmocat]

4. It is his primary tool to control a simple minded and distracted citizenry

He has not grand plan or well thought out strategy, he just makes it up as he goes along. BUT, his master skill is being able to manipulate the lesser spirits of the human soul.

His number one motive in ANYTHING he says or does is to keep "the base" (which was already brainwashed by decades of eagerly shoving in conservative media propaganda) tweaked out and completely distanced from reality. That is how he controls them, and uses them as a sledge hammer against the rest of the country. Say or post something that is completely false or made up, they are put in a position to have to defend (and with it believe it themselves) the completely indefensible.

His second motive is to keep throwing $hit out time after time after time, to confuse and overwhelm the media and population at large. With everything at this point completely muddled, the zombie base (and the GOP and conservative media) all being united in screaming one thing (as completely insane as it is 99% of the time) wins the day.

He revels in destroying the country, but that is just a bonus, and is a result of him being him.