Donald Trump may be a lot of things, but one thing he most certainly is, is a birther. After the Obama birth certificate died down, well over a year later, Trump jumped on the bandwagon and claimed he was the one who finally put the issue to rest, that should have been put to rest long before. It kinda had - nobody was talking about it at that point except Trump.
I guess he could try to claim the same for illegal immigration, although that never really went away.
But more recently he decided to try the same tactic on Ted Cruz. Except it's fizzling fast;
Washington (CNN) A New York judge has dismissed a petition that claimed Ted Cruz was not eligible to run for President of the United States because he is not a "natural born citizen."Judge David A. Weinstein's ruling was procedural, stating that the petitioners, Barry Korman and William Gallo, failed to submit timely objections, which stripped the court of jurisdiction over the petition. His ruling did not consider the actual merits of whether Cruz, who was born in Canada, qualified as a natural-born citizen in this year's presidential election.
Ultimately this is a sideshow and will go nowhere. As the article points out, the horse is out of the barn. And in reality, the case is baseless. Trump knows it's pointless, just as he did with Obama but it's a tactic and he's using them all.