Here's Donald Trump's latest organizing embarrassment: Two of his adult children did not know they had to register as Republicans more than six months ago to vote in New York's April 19 Republican primary. "They were, you know, unaware of the rules, and they didn't register in time, so they feel very, very guilty -- they feel very guilty," Trump said during a telephone interview with Fox News' "Fox and Friends" on Monday morning. One of the hosts commented: "Oops." Trump said that he understands the mistake and that it's "fine" that his children Ivanka Trump and Eric Trump, who...