Just hours before the Republican National Convention played a campaign video Wednesday night showing Mitt Romney at the Western Wall in Jerusalem, his single-biggest financial backer -- billionaire casino magnate Sheldon Adelson -- made a rare public appearance, telling reporters at a Republican Jewish Coalition (RJC) event that the GOP presidential candidate is “very pro-Israel” and is “going to defend what he thinks is best for the relationship” between Israel and the United States.

Sheldon Adelson and wife Miriam arrive at the Republican Jewish Coalition's event in Tampa on August 29th, 2012. Adelson is greeted by U.S. Senate candidate Ted Cruz, of Texas.

But Adelson, who with his wife has given $10 million to the pro-Romney Restore Our Future super PAC, never had the chance to expand on his views about the Middle East or respond to questions about his mega donations to the GOP cause. As soon as the frail but feisty 79-year-old chairman of the Las Vegas Sands Corp. sat down -- after making a grand entrance clutching a cane and assisted by his Israeli-born wife -- RJC coalition organizers chased away members of the media, repeatedly shouting: “The event is over! We’re going to close this down!”

(Later that evening, a producer with the radio show Democracy Now sought to question Adelson — being accompanied by Karl Rove — while he was being taken by wheel chair to a fourth floor corporate skybox at the convention. In an incident caught on videotape here, the producer, Mike Burke, reported that a woman identified as Adelson’s daughter grabbed his camera, took it into the skybox and threw it on the ground. Burke said the daughter later apologized.)

Lior Mizrahi / Getty Images U.S. gaming tycoon Sheldon Adelson and his wife Miriam arrive to hear Republican presidential candidate, former Massachusetts Gov. Mitt Romney delivers foreign policy remarks on July 29, 2012 in Jerusalem, Israel.

The brief appearance by Adelson came at a spirited event where top members of Congress rubbed elbows with wealthy GOP donors and “Obama ... Oy Vey!” buttons were freely distributed to attendees. At the same time, new details emerged about Adelson’s role in steering supersize checks to groups working to defeat the president and elect Republican members of Congress.

Shortly before Adelson arrived, celebrity rabbi Shmuley Boteach, author of “Kosher Sex” and a one-time spiritual adviser to Michael Jackson who is now running as a Republican candidate for Congress from New Jersey, boasted that Adelson and his wife had recently given $500,000 to “my super PAC” and that they were “heroes of our community.”

Boteach later told reporters that he had then dined with Adelson this week during the RNC convention. “Well, I mean, look they’re friends,” he said of Adelson and his wife. “They don’t need me to tell them where to give their money. They’re very savvy political donors.”

As for the super PAC, called “Patriot Prosperity PAC,” Boteach at first said that, while “we obviously don’t have any contact with them,” it was “set up by the professionals who run my campaign.”

NBC's Michael Isikoff reports on Republican VP pick Paul Ryan's meeting last night in Las Vegas with some big-dollar GOP donors, including casino tycoon Sheldon Adelson, for a private talk about the campaign.

Although the half-million dollar donation by Adelson and his wife to the “Patriot Prosperity PAC” had already been reported, Boteach’s reference to “my super PAC” and his reference to it being “set up” by his campaign “professionals” seemed to raise fresh questions about whether the donations complied with federal election laws. Those laws bar campaign committees from coordinating their activities with supposedly independent super PACs -- which are allowed to take unlimited donations.

But when pressed by reporters about his comments about the origins of the group, the rabbi corrected himself.

“No, no, no, no, no, no, no,” he said when asked if his campaign staff had set up the super PAC donations. “Let’s not pull me into something that I am not -- I said the people who run my campaign are the ones who tell me what we’re allowed to do and what we’re not allowed to do. And we are allowed to tell the people who support us that if they want to support us, there was a super PAC. And that’s what we did. That’s exactly what I meant.”

Adelson’s contributions in the 2012 election --- now, combined with those of his wife, total more than $40 million -- have stirred controversy, in part because of his hardline views on Israel (he is a close friend of Israeli prime minister Benjamin Netanyahu) but also because of ongoing federal investigations into his gambling empire over allegations that it has paid bribes to Chinese officials.

Rabbi Shmuley Boteach, a candidate for U.S. Congress from New Jersey, discusses Sheldon Adelson's gift to the Super PAC supporting Boteach's campaign.

Also this week, Bloomberg News reported that Adelson’s Sands Corp. -- which generates more than half of its multibillion-dollar revenues from four casinos in Macau -- could see its profits soar if Romney were elected and fulfills his pledge to demand that China loosen currency restrictions, allowing the value of the yuan to rise against the dollar.

Adelson’s appearance was the highlight of the RJC event -- partly sponsored by Comcast (owner of NBC News) -- which was attended by other big GOP donors such as hedge fund billionaire Paul Singer. Also present: GOP Sens. John Thune of South Dakota and Lindsey Graham of South Carolina, House Majority Leader Eric Cantor, and Reps. Michele Bachmann of Minnesota, Allen West of Florida, Ed Royce of California and Renee Ellmers of North Carolina.

The event -- briefly interrupted by two protesters who loudly denounced Israeli policies towards the Palestinians and were quickly evicted -- was marked by multiple denunciations of Obama’s policies to Israel.

“I don’t know how there are any Democratic Jews,” said GOP Rep. Billy Long of Missouri. “The way the president has treated [Israeli Prime Minister] Bibi Netanyahu and the land of Israel, I don’t know how any Democratic Jew can still be a Democrat.”

NBC’s Jamie Novogrod also contributed to this story.