I've gone on in some detail on other threads about this, but here is the short version. Standing, as it relates to this matter, is a constitutional requirement. It stems from Article III's requirement that the federal judiciary hear only "cases and controversies."
In order to have standing, a plaintiff must demonstrate individual and particularized injury that differs from the injury suffered by the public at large. Berg's problem is that his injury is the exact same injury that everyone else in America has: the "injury" of being offended that constitution may be violated, or, perhaps, the inability to vote for the candidate of his choice. That's also the same injury suffered by the public at large.
Because Berg can't show that his injury is different than that of the public, he doesn't have standing.
Thanks, that makes sense once I get my head around it but.... there must be a way to force the DNC and the Candidate to follow the law. In the absense of someone in some government institution stepping up, how exactly do you file suit to halt this sham election or at least forst the other party to prove eligibility? Surely there's a way to move it forward???