I think Deacman is probably correct that Obama probably rode higher popularity numbers when he entered the WH, and he's correct that that election was very close until the last week. About a week out hit the 1 year anniversary of the Iranian hostage crisis, and even though Reagan frightened a lot of folks at the time, the voting broke his way big time in that last week - folks just wanted a change. That said, the atmospheres in DC were very different in the 80s than they were the last 8 years. The Dems had congress in the 80s, but at the end of the day, Reagan and Tip O'Neill would get things done. Reagan didn't face the massive resistance to literally everything he wanted to do that Obama has. Given that hostility, it's impressive that Obama's favorability numbers have meandered to north of 50%. (Although I believe part of the reason for the positive numbers is the horrific slate of candidates that both parties had this time around.)
Reagan did not get attacked personally or racially or his family as deeply and as heinously as Obama, his wife and his kids were. This should not be in dispute by anyone. Reagan's Americanism was never attacked. His faith was never attacked.
People didn't like Reagan's policies for a while, but he was never treated like Obama has been.