Legal Challenges
You're asking if there is any way for the Illinois GOP to prevent Arthur Jones from being the Republican candidate for the US House.
Yes. They can challenge the validity of the signatures he collected to qualify for the ballot or accuse him of other violations of the election c...
-1 for the unrelated commentary, especially the suggestion that letting a Nazi run in the name of your party should be encouraged as an "exchange of ideas", or that Jones - a Holocaust denier, antisemite, former member of the American Nazi party, and someone described by the Republican party as a Nazi - is merely "portrayed as a Nazi" by "anti-Republican and anti-conservative" news media.
Apart from the fact that the "point of view" of Nazis is genocide, freedom of association is an essential part of free speech. The idea that political parties should not only have to accept, but actually encourage that Nazis use their image and platform to reach their goal of murdering every last Jew is quite unreasonable. That you don't trust reputable sources (or the GOP, or took a couple of seconds to check out Jones's website yourself) is your issue, but why include that in an answer? As-is, it sounds too much like unrelated Nazi apologism to me. I stand by my -1.
The entire purpose of the First Amendment of the US Constitution is to protect ugly, unpopular and even detestable forms of speech and expression. We don't need the Bill of Rights to protect pretty, popular and likable forms of expression. Therefore, because I believe in and support the Constitution, I support the rights of Nazis, KKK members, black panthers and other hateful people to express themselves. Besides, I am not afraid of their views. The good people of the United States will always win over such hateful ideologies. So I stand by what I wrote in that respect....
Second, I wrote "portrayed" only because I haven't researched the man's background myself. I'm relying on second-hand information, in the form of headlines, from different news media outlets. I don't believe what the media writes at face value. I will not call a man a Nazi unless I've done my own research and come to that conclusion on my own. I didn't research the claims against Arthur Jones because they are beyond the scope of the question. So I stand by what I wrote in that respect, as well.
There's nothing in my answer that even suggests "Nazi apologism". You're way, way off. That's about as accurate as me accusing you of being a Nazi because you live in Germany. Not that it matters, but I'm Jewish and my ancestors suffered many of the horrors perpetrated by the Third Reich. Maybe you can focus on the substance and actual words of my answer, instead of your biased impressions. @tim
why would we want to prevent a candidate from running: note that this is not exactly what I asked, I asked if the GOP can prevent Jones from running as a Republican. He can still run as independent or with another party, just not as Republican. If I were a Republican, I wouldn't be happy with having a literal Nazi on the ballot with the same party name, for reasons that should be obvious (and as mentioned in the question, the GOP is just as unhappy as I would be).
@Michael_B I take back the "sounds too much like Nazi apologism" because it's too harsh (and I never meant to attribute any motivation to you, just to criticize the words you used and the impression they can leave), but I stand by the rest of my comments (specifically regarding the freedom of association of parties and the needless attacks on the media in relation to a man who is obviously a Nazi - a fact that seems to be uncontested by anyone but the man himself). I still think that this criticizes your actual words, not my impression of them.
So this answer is being downvoted because I didn't explicitly call Arthur Jones a Nazi? Too bad. I never said he wasn't. I just said I hadn't done my own research and therefore wouldn't apply that word directly. On a daily basis, people on "reputable sources", such as CNN and MSNBC, call the President of the United States a Nazi. Should I believe that, as well? Actually, in that case, I've done my research, and can say with 100% certainty, that Donald Trump is in no way, shape or form a Nazi.
I didn't downvote, but I think there are a few problems with this answer. The question assumes he already manages to get the Republican nomination, so "don't get the nomination" doesn't really answer the question. The "Why?" section is also not what I asked, as I mentioned in a previous comment. It's also not clear to me that gerrymandering is a factor in this specific case, and your comments about Gerrymandering in general are rather off-topic.
In addition, the phrasing in your last paragraph "a GOP candidate who could be portrayed as a Nazi" is somewhat unfortunate, as it's very clear that this is an actual literal neo-Nazi, not someone who is somehow unfairly portrayed as such by any (liberal) media. I also don't understand why you mention the First Amendment in the comments, as no one here is saying that Jones should be prevented from saying anything.
To make an analogy, it's the difference between Jones publishing his own website with his Nazi crap, or him publishing his crap on my website. He can do with his website what he wants, but I'm sure as hell not letting him anywhere near my website, as it's, well, my website.
Preventing somebody from running for office is, at least in my view, an infringement on that person's freedom of expression, which is a violation of that person's First Amendment rights. That's why I mentioned it. (Also, the First Amendment isn't only about restricting people from "saying anything".)
And, once again, I will not refer to a person as a "Nazi" unless I have come to that conclusion on my own. As I have not done any research on Arthur Jones' background (he's almost certainly not going to Congress and your question wasn't about his political views, so I didn't study him), I will not use the term directly.
But it's not about preventing anyone from running from office. All I'm asking is if the GOP can say "good luck with your election, but not with an (R) behind your name". Think of it as a Trademark issue: I'm free to sell as many burgers as I want, but I can't call my restaurant "McDonalds". I will not refer to a person as a "Nazi" unless I have come to that conclusion on my own: He was literally the leader of the American Nazi Party. What more do you want?
@Carpetsmoker, "He was literally the leader of the American Nazi Party". ... Let me try once again: I.DID.NOT.KNOW.THAT. I never bothered to research this guy's background because that was not relevant to your question and he's a complete long-shot to win the seat. In a few months, he'll shift back to obscurity, so I didn't waste my time researching him. I'm not sure why this is so difficult to understand. I don't care enough about him to research his background.
And a way "to prevent" a candidate from running is literally what you wrote in your question. The right / fair / honorable way to win / lose is through primary elections. And keep in mind, it was Republicans themselves that put him on the ballot. He didn't just put himself on the ballot. He needed to collect enough signatures from registered Republicans in the district to qualify.
So a fair interpretation of your question is: "How can some Republicans disenfranchise other Republicans when the first group doesn't like the candidate fielded by the second group and the first group didn't bother fielding their own candidate?" That's really what you're asking.
Discussion on answer by Michael_B: Do…
Discussion on answer by Michael_B: Do…