Delegates at this week's Republican National Committee meeting in Florida this week say they're being threatened from some of Donald Trump's supporters after his complaints that the party's nomination process is "rigged."Now, they're concerned about the potential for violence as the likelihood of a contested GOP convention grows."Several people said now is not the time to change the rules," Colorado GOP Chairman Steve House. "Most people don't want to make news and are being very, very careful. There's an element of fear in the process."House came under fire after his state's process resulted in Ted Cruz getting all of its delegates, with Trump complaining loudly about the delegates being chosen through a state convention rather than through a traditional primary.The chairman said that one email warned him to hide his family and "pray you make it to Cleveland," and another man called his cell phone and told him to put a gun down his throat, and that he'd come help him do it if he called back in two minutes and he was "still there."House said that there were many of the 4,000 to 5,000 calls he's gotten that ended with conversations, but he has referred many violent calls to the police. His phone is still ringing this week while he's in Florida for the RNC meeting.Many other delegates and party chairmen shared similar stories, including one who ended up face-to-face with a supporter who promised there would be "bloodshed" if Trump does not win the nomination, Politico reports."The Trump campaign needs to publicly reject bullying and threats of violence," the chairman, who was not identified, said. "They haven't, yet. It's not okay to give supporters threatening violence a wink and a nod."Trump's campaign seems to be shifting after he hired veteran strategist Paul Manafort as his convention chief, who is pushing Trump to temper some of his rhetoric. One campaign operative, a Manafort ally, said the campaign's former chiefs, led by campaign manager Corey Lewandowski, did not do enough to rein in violence that has marked some of Trump's rallies.But it may be too late, some delegates worry."I've had these thoughts quite a bit and had these discussions with people who think I'm an idiot for wanting to go to Cleveland," said Craig Dunn, a John Kasich supporter who said he is worried about leaving the arena if Trump loses.Concerns have also grown after Trump ally Roger Stone threatened to disclose hotels and room numbers of anti-Trump delegates.Dunn said the threats have eased in recent days, but he expect they'll start up again after his state's primary election on May 3, and he is frustrated that Trump has been whipping up crowds but not dealing with the fall out."You can take advantage of the people's lack of understanding, he said. "He may premeditate when he does that and chuckle when he walks off the podium, but [his supporters don't know when to turn it off."