50 senior Republican national security officials have signed a letter warning that Donald Trump would “risk our country’s national security and well-being.” Those who signed this letter are helping Rudy Giuliani make his point to the American people.

The letter, which was made public Monday, was signed by a group of GOP national security experts including former CIA Director Michael Hayden, former director of national intelligence John Negroponte and former Secretaries of Homeland Security Tom Ridge and Michael Chertoff. All 50 of those who signed the letter said that they will not vote for Trump and all of them, Giuliani said, represent exactly what Trump is running against.

“I believe it makes Donald Trump’s candidacy really clear: He’s running against the Washington insiders. You just heard from the Washington insiders,” Giuliani said in an interview on Fox News’ “Fox and Friends.” “These are the people who have been running policy for the last eight or ten years, 12 years. The American people have delivered a judgment on that. They say America is headed in the wrong direction. These are the people who headed it in the wrong direction.”

The former New York City mayor says he personally knows many of the officials who signed the letter and has even done business with a number of them. However, this doesn’t stop Giuliani from calling this group the group for regularly moving back and forth between government work and jobs in the private sector. He said that those who signed the letter wouldn’t support Trump because he comes from outside the world of Washington, he isn’t part of the “club,” and “they don’t know him.”

“Everybody who has run for president has been part of the club, right? Mitt Romney was part of the club. John McCain was part of the club. John Kerry was part of the club. Al Gore was part of the club. Trump is not part of the club. Thank God,” Giuliani said. “They’re all part of the Washington insider group. It makes Trump’s points dramatically that he is the outsider representing everybody else who doesn’t have a lobbyist in Washington.”