After a decades long campaign of delegitimization and propaganda directed towards Israel, these results are reassuring. Only 21% of American regard the Palestinian Authority favorable.
From Gallup: Americans remain staunchly in Israel's corner
...Americans' stance on the Israeli-Palestinian conflict is as strongly pro-Israel as at any time in Gallup's three-decade trend. Sixty-four percent say their sympathies in the dispute lie more with the Israelis, tying the high previously recorded in 2013 and 1991.
Also reassuring is the decline the percentage in Americans who are undecided or neutral to 16%, the lowest to date. This implies that Americans are learning more about the conflict, and are solidifing their support for Israel.
Results for this Gallup poll are based on telephone interviews conducted in February 2018, with a random sample of 1,044 adults across America, aged 18 and older