o politics for the last decade, it would appear very clear that Democrats and liberals are much more pro-palestine than Republicans. You may also have noticed democrats are the ones decrying sexism, and anti-gay sentiment.
This seems odd considering the vast bevy of abuses that women's rights in palestine face every day or the fact that being gay by itself is illegal in the Gaza strip and in the West Bank, there is no protection for gays anywhere accept in Israel, which ironically is the place that Democrats and liberals are more against than all other political sides in America.
If Democrats and Liberals support Palestine despite the clear seemingly incompatible views, there must be some link between the two sides.
Ben Shapiro has suggested it seems from both sides hatred of Western civilization, he argues that inherently the left finds the west unfair, racist, sexist, transonic, and so forth. This would explain why people like Bernie Sanders become so popular with the left, they attack the so called unfairness of the west. The middle east doesn't see the west as unfair but rather immoral. The highly islamic fundamentalist views in the middle east are at odds with the views of America as well as the social trends in the american public and thus the two are at odds. Thus, both detest western civilization and they are brought together by that shares belief, this at least being Ben Shapiro's argument.
Another logical view on the matter of the seemingly odd bond between the left and Palestine could be the Left's fixture on islamaphobia. After every terrorist attack, conservatives come out and say we have to do something about it, libertarians look to the actual root of the problem and say our interventionalism should be stopped and we should stick to our own affairs in order to stop angering other countries, and liberals come out and target islamaphobia. This idea that anything remotely hinting to the idea that radicals exist in fundamentalist Islam causes many alt-left liberals to shudder. Having placed the badge of unprivileged on Muslims, the idea that radical Muslims exist is at odds with the left's habit of placing virtue upon anyone they see as under privileged, and thus islamaphobia or percieved islamaphobia is highly angering to the left. This anger translates into a need for action and can therefore translate into support for Muslim countries as a percieved sign of solidarity with islam.
The last reason I could propose for the reasoning for support for palestine from the left is anti-Semitism. Historically, there has never been a time after the beginning of Judaism where jews have not faced persecution, and this once again is occurring as groups like hamas(which runs a segment od the Palestinian government) call for the eradication of the Jewish people. It's not a far cry to think that at least a portion of the pro-palestine views originate from anti-Semitism, however the popularity of Bernie Sanders would seem to contradict a wide spread hatred of Israel. However it still seems odd that the most western-like country in the middle east, israel, western meaning synonymous with freedom of religion, of speech, of sexual orientation, and mang other freedoms, would be the despised by a large percentage of the democrats (31% or twice as likely than the normal population).
Whatever way you look at it, it still seems odd that the democrats would be as split as they are on the topic, while republicans sympathize with israel at a rate of 74%, democrats sympathize with israel at a rate of 33% while 31% sympathize with palestine. Odd for the party that calls Trump anti-Semitic or Hitler, to be much more anti-israel than the supposed "facist" party that they denounce as anti-Semitic.