Wait, so you're saying this is Obama's good economy but Trump's fault with regard to homelessness?
1. Things Trump cite, like jobs added and stock market going up, are following the trend from the Obama years. This on the other hand is a reversal from what happened under Obama.
2. Some things can be quickly affected by police (homelessness) some things are more dependent on fundamentals (overall state of economy).
For both those reasons some things can be attributed to Trump more plausibly than others.