As noted earlier, the only candidate for the Democratic nomination for U.S. Senate, Josh Mahony, withdrew a few hours after the primary filing deadline had closed.  This article says the party can replace him if he has a “serious health” problem.

When Mahony withdrew, he said there are “family health concerns” but he did not specify whose health he was talking about.

Meanwhile, this story suggests that Mahony withdrew after he was informed that the Republican Party had done opposition research on him, and found damaging information.  The story says the party had this information before the filing deadline, but did not communicate it until after the hearing.