>Americans have been trained to have a strictly binary, categorical view of issues instead of looking at each issue as something with its own set of properties to explore.
Perhaps that's true of some (perhaps many) Americans, but certainly not all. Please don't paint 330 million individuals with the same broad brush. If for no other reason than you're doing exactly what (taking a binary, categorical view of a gigantic group instead of treating individuals as individuals) you're complaining about.
For me (as well as many other Americans), I recognize that context and nuance are important when considering most issues.
Assuming that tweets or political slogans represent the views of all (or even many) Americans is shallow indeed.
The devil (as well as the solutions) is always in the details, whether it be the minimum wage, broadband competition, healthcare or dozens of other issues.
Many people (myself included) are ignorant of the details surrounding a variety of issues unless it directly affects them.
However, many (if not most) have a nuanced understanding of issues (at all levels of government) that impact them.
The nationalization of party politics (helped along quite a bit by the decline and disappearance of much of the local journalism in the US) creates least-common-denominator messaging that ignores any nuance or context whatsoever.
As for Assange, it's not a left/right dichotomy at all.
In fact, many who generally vote (D) are among Assange's biggest supporters, and many who generally vote (R) are among his biggest detractors.
IMNSHO, it has much more to do with whether or not you believe that Assange can get a fair trial in a US Federal court.
There are dozens (50 state court systems, many more municipal/county/territorial court systems) of other courts in the US, but the Federal court system is generally among the fairest of US court systems. Especially if there's a lot of publicity surrounding a particular case -- as there is here.
And Assange will be tried in Federal court.
The man himself doesn't think so, or he wouldn't have cloistered himself in the Ecuadorian embassy for seven years.
Given that no journalist has ever been convicted under the 1917 Espionage Act[0], under which the really serious charges against Assange was indicted, it seems unlikely in the extreme that he'd be convicted of those charges.
The charges under the Computer Fraud and Abuse Act[1] do not carry heavy sentences, nor (at least as I understand it) is the evidence of violations of that law very strong.
As such, it's quite likely that if Assange hadn't jumped bail and hidden out in the Ecuadorian embassy, all this would have been over and he'd have been banging Swedish girls again for at least a few years.
As someone who generally votes (D), I'd like to see Assange acquitted and let him move on.
His credibility has suffered mightily, but most of that (IMHO) was a result of his own actions and statements (Seth Rich? Really?).
Regardless, you're flat wrong about Americans as mindless morons parroting their particular party line. Sure there are some who do so, but certainly not all (or even most).
[0] https://en.wikipedia.org/wiki/Espionage_Act_of_1917
[1] https://en.wikipedia.org/wiki/Computer_Fraud_and_Abuse_Act
Edit: Added referenced links.