The charts above are from a recent Gallup Poll -- done between June 13th and 19th of a random national sample of 3,560 adults, with a margin of error of only 2 points.
It shows that Hillary Clinton has a 10 point advantage over Donald Trump in favorability rating -- and Trump has a 10 point disadvantage over Clinton in unfavorability. That gives Clinton a 20 point advantage in net favorability (favorable minus unfavorable).