While Donald Trump picked up a big endorsement from grassroots conservative favorite Sarah Palin on Tuesday, it's Sen. Ted Cruz who is receiving the support of leaders with direct ties to the 1960 signing of the Sharon Statement by 90 members of Young Americans for Freedom (YAF), an event that represented the founding of modern conservatism.

Richard Viguerie – the 82-year-old pioneer of direct-mail fundraising who served as executive director of the YAF in 1962 and worked on Barry Goldwater's 1964 presidential campaign – tells Breitbart in a new interview that, "Ted Cruz is the best conservative candidate since Ronald Reagan."

"He's what we've been waiting for ever since Reagan. He checks all our boxes. He's everything we've wanted in a candidate," he said, noting that Cruz is "our best debater, our most articulate fighter."

Viguerie said that Cruz is the only candidate who can unite all six main voting blocs that comprise the Republican Party.

"He unites the party in a way that no other candidate can," he said. On the other hand, Trump is seen as ignorant of the bible and disrespectful towards women, which alienates Christian voters, and his authoritarian policies alienate libertarians, he said, according to the Financial Times.

Just as valuable is Cruz's ability to appeal to Reagan Democrats. "Cruz appeals to Reagan Democrats. His position on the issues of importance to Reagan Democrats is basically the same as Trump, it's just that Trump articulates it differently," Viguerie said. "Cruz is there in terms of having the same positions on issues of importance to Reagan Democrats. He has a lot of the appeal Reagan had to Democrats on economic, national security, and cultural issues."

Last week, 76-year-old Morton Blackwell – founder of the Leadership Institute, YAF member in the 1960s and longtime member of the Republican National Committee – endorsed Cruz, saying he "has consistently demonstrated his deep commitment to conservative principles."

Brent Bozell III, who was only five years old when YAF members signed the Sharon Statement at the Connecticut home of his uncle William F. Buckley Jr., also endorsed Cruz in an interview with Breitbart.

"Yes, I support Ted Cruz," said Bozell, son of Brent Bozell Jr., the ghost writer of Goldwater's 1960 book "Conscience of a Conservative."

"It's clear cut that you are either with the establishment or you are with Ted Cruz. That is the new reality. It is the Republican Party that has disdain for conservatives," he said.

"Ted Cruz has made virtually all of them [in the Republican establishment] feel uncomfortable. The sin he commits is honoring his promise," Bozell says. "What they, the GOP establishment, want is unanimity in dishonesty. That's why I urged Ted Cruz to run for president. I've urged him since about five minutes after he was elected to the Senate [in 2012]."

He added, "The more this plays itself out, the more it is being established that Cruz is the real conservative and Donald Trump is a charlatan."