Read the article (link below). Actually things have gotten quite ridiculous; yet Trump has kept it a focus. Many of the GOP candidates (including Trump) eligibility has been challenged.
...Cullen Fergus, a former state GOP chairman, challenged Donald Trump’s ballot application, arguing that the billionaire businessman’s views don’t align with the Republican Party.
Another challenge came from Robert Laity, a resident of Tonawanda, N.Y., who describes himself as founding president of the Society for the Preservation of Democracy and Human Rights, and who has called Obama a traitor. He challenged four Republicans — Cruz, Sen. Marco Rubio, former Sen. Rick Santorum, and Louisiana Gov. Bobby Jindal — on the grounds that at birth, each had at least one parent who wasn’t a U.S. citizen....
http://trailblazersblog.dallasnews.com/2015/11/regardless-of-canadian-birth-ted-cruz-survives-ballot-challenge-in-new-hampshire.html/