Sen. Rand Paul’s (R., Ky.) most prominent pro-Israel backer, who funded the senator’s 2013 visit to Israel, is throwing his support fully behind Gov. Scott Walker’s prospective presidential campaign, he told the Washington Free Beacon.

Rich Roberts, a major Republican donor from New Jersey, has been central to Paul’s Jewish outreach efforts. The former pharmaceutical executive, who has been described in the press as one of Paul’s "ambassadors to the Jewish community," has hosted private receptions for the senator over the past few years, assisted as an informal adviser, and sponsored his highly-publicized Israel trip.

While Roberts said he likes Paul, he said he is committed to supporting Walker when the Wisconsin Republican enters the presidential race.

"I like Rand Paul a lot, our relationship goes back now about three or four years. I like him as a person, I think he’s very well-intended," said Roberts. "But I think that Scott Walker is [a greater] likelihood of being the next president. I think Scott Walker is also a tremendous individual."

Roberts’ relationship with Walker goes back to his recall campaign, when the New Jersey Republican contributed $50,000 to the Wisconsin governor because he admired his strength and resilience on labor unions.

The CEO of a pharmaceutical company at the time, Roberts said he received an onslaught of hate mail from union members after his contribution to Walker was disclosed. Instead of backing down, Roberts decided to give the governor another $50,000—and received an admiring phone call from Walker thanking him for "doubling down."

However, Roberts has also been Paul’s most high-profile defender on Israel issues, even as he has strongly criticized the senator’s father, former Rep. Ron Paul.

Both Walker and Paul have made efforts to reach out to the Jewish community in the past few weeks.

Last Monday, media mogul Mort Zuckerman held a private reception for Walker at his home in New York. The meeting was hosted by the Conference of Presidents of American Jewish Organizations, and attendees included the Conference’s executive vice president Malcolm Hoenlein, former Corporation for Public Broadcasting Chair Cheryl Halpern, and American Friends of Likud President Gerald Platt.

Walker discussed national security issues, and reiterated "his intention to on day one scrap any bad [Iranian nuclear] deal the president commits us to," according to one attendee.

The Wisconsin Governor stumbled several times on foreign policy earlier this year, but sources in the room said he seemed to have an improved grasp of the issues after working with a team of foreign policy advisers.

Attendees also said Walker was well received by the group.

"Initially a lot of the people there didn’t seem to have much of a connection with him," said Roberts. "But he was overwhelmingly received after he spoke. They were taken back by how capable and knowledgeable he was."

Paul also spoke at a Torah Umesorah event in New York this Monday, where he emphasized his work on legislation that would revoke aid to the Palestinian Authority.

Paul was introduced at the event by Roberts, who praised the senator’s "tremendous intellectual honesty."

However, Roberts told the Free Beacon that he was not involved in organizing the event or inviting attendees.

"I was really just there to introduce Rand, and I’m always happy when I see him," said Roberts. "By far and away the majority of my efforts and resources are for Scott Walker."

The Paul campaign did not return a request for comment.