I would agree with you on that Iraq was a colossal blunder. But your way offside regarding the 44th.

Obama inherited a broken economy held together by TARP, and billions in budget deficits spent dealing with the Taliban and Iraq. He got out of Afghanistan yet hunted down Bin Laden. He crossed the Rubicon on health care and permitted 20 million to access health care. Perhaps not the most efficient compared to single payer he improved the welfare of those with pre-existing conditions. 
He tried to implement some gun restrictions after Sandy Hook, but was unable to get republican support. 

Trump is a racist who openly lied to the country, fails to comprehend the Constitution and US distinctive institutions, stands idle after 630 were shot in 2 mass shootings, allowed mentally incapacitated to buy guns, is a stooge for Russian oligarchs, tossed out paper towels to clean up a hurricane, continually spills soup on his tie, is factually ignorant and is the biggest fake the world has seen.