Corporations, and any community chest, fund, or foundation, organized and operated exclusively for religious, charitable, scientific, testing for public safety, literary, or educational purposes, or to foster national or international amateur sports competition (but only if no part of its activities involve the provision of athletic facilities or equipment), or for the prevention of cruelty to children or animals, no part of the net earnings of which inures to the benefit of any private shareholder or individual, no substantial part of the activities of which is carrying on propaganda, or otherwise attempting, to influence legislation (except as otherwise provided in subsection (h)), and which does not participate in, or intervene in (including the publishing or distributing of statements), any political campaign on behalf of (or in opposition to) any candidate for public office.
I bolded the Johnson Amendment, which is the political part. It has been generally taken to mean that broad party events are permissible as they don't support or detract from a specific candidate.
This is a shock to everyone here, I know, but it's possible the people on Twitter that that Newsweek article is talking about may not be fully cognizant of the law, and are just tweeting their feelings. It also may be possible (may be, I'm not 100% sure) that Newsweek wrote an "article" critical of the Idaho GOP based on nothing more than some Rando's tweeting in an effort to give those tweets a veneer of legitimacy that they don't actually have, and make it seem like the Idaho GOP has done a Bad Thing
tm.
