The charts above were made from a recent Gallup Poll -- done between July 20th and October 19th of a random national sample of 44,728 adults, with a 1 point margin of error. It shows that President Obama has a job approval rating of 52% ( more than half of the population) and it has been climbing for at least the last four quarters.
Obama's job approval rating compares very favorably to that of several past president's -- Eisenhower (61.3%), Reagan (53.5%), and Clinton (59.1%).
This does not guarantee the election of Hillary Clinton, but it certainly doesn't hurt her chances either. Trump has been campaigning on the idea that a Clinton presidency would be a continuation of Obama's presidency. It looks like that is not an idea that upsets a majority of voters.
The fact is that the public is a lot happier with President Obama than they are with the Republican Congress (whose job approval remains below 20%).