To not like Obama does not mean I like Trump or Bush. I take each on their own merits. So dont come at me with "Yeah, but look at what Trump/Bush did". Irrevelent.

Obama: He went too far in the freebie end of the spectrum. Obama phones??? What the heck.
Welfare and Racial issues seemed to peak during his term.

He failed to go to 4 star generals funerals, but sent a team to Trayvon Martins. He waited too long to speak out against Furgeson Missouri riots, and jumped into the "he could have been my son" rhetoric too soon too long.

He weakened the US on the world stage by never having clear policy on foreign matters.

His last week in office he shipped how many millions in cash to Iran? On a pallet. On a military plane. His reasons were sketchy at best.

He appeared to many as the Anti Bush president, rather than the pro-Obama president. Like many who get in office, rather than make their own path, they spend an inordinate amount of time undoing the prior presidents things. (Trump does too).

He dismissed several top generals for less than appropriate reasons, and weakened the military. He also cut back on the number and spending in military.

I ran out of time, and cant research anything now, this is all off the top of my head.

And.... i question his loyalty to the US, and his family ties/loyalties to other types of governments. I think he was trying to serve too many ideologies.