Sorry it's not a violation of Federal Election law for Glenn Beck or anyone else to tweet photo-shopped images or tweets of political candidates. FreeRepublic posters would have been shut down long ago.
It was a FAKE TWEET, and Trump claimed its author was TRUMP, and it is illegal in an election to disseminate something and attribute it to a candidate falsely. Look it up. I posted the law a few days ago. You cannot CLAIM to be speaking AS the candidate. You can’t distribute, let’s say a leaflet, or letter to the editor or whatever, and CLAIM that it is from the CANDIDATE. Particularly when you are WORKING FOR the candidate who you are doing the dirty trick on BEHALF of. And that you INTENTIONALLY knew. You need to brush up on “dirty tricks” which is a large subject about which, in electioneering and in election law, is a very serious subject.