Taiwan is not favoring China. They are very much against being absorbed into China.
This would be a military invasion like one done by Xi's best friend Putin, but more competent. As a result of said invasion there is a large likelihood of a shooting war between China, US and probably involvement of Japan, Australia and UK.
This will completely wreck world economy, destroy a democratic country (Taiwan) and has possibility of slipping into a nuclear conflict. Not to mention that North Korea might take the chance to give it a go at invading South Korea at same time with US occupied.
As far as Trump goes, remember that a)Only half of US voted for him and b)Other choice was also pretty terrible.