Josh Mandel, the 34-year-old Ohio State Treasurer and Republican Senate candidate, is a nice Jewish boy from a nice Jewish family. His grandfather was a Holocaust survivor. His father, a lawyer, was active in the Jewish Federation, and Mandel grew up playing softball for the Cleveland JCC. His wife, Ilana, works for the Cleveland Hillel. On the campaign trail, he plays the part. “When he speaks to the Jewish community, he talks about his Bubbe,” one Ohio Jewish voter actively involved in the state’s Jewish politics, told me.

For Republicans, this is all very good news. Real Clear Politics recently placed Democratic incumbent, Sherrod Brown, ahead of Mandel by a measly three points. Though Ohio’s 150,000 Jewish voters make up just 1.3 percent of the state’s electorate, they are a crucial part of the Democratic base. (Brown won 78 percent of the Jewish vote in 2006.) If Republicans shave off even just a small portion of those votes, it would be, in the words of Matt Brooks, director of the national Republican Jewish Coalition, “A big win.”

What should be even better news is that Mandel married into one of Ohio’s preeminent Jewish families, the Ratners—a Jewish clan so dynastic, the Cleveland Plain Dealer once published their family tree. But his extended family has been somewhat less than supportive; indeed the Ratners are longtime supporters and fundraisers for Democratic causes. Ronald Ratner, a cousin of Ilana’s father and an executive for Forest City, the Ratner family’s national real estate company, hosted a lunch for Obama in his home last year that was attended by the vice president. Dan Ratner, another cousin, works on the Obama campaign’s technology team. Michael Ratner, a human rights attorney in New York, is defending Julian Assange, and his brother, Bruce, the owner-developer of the Barclay Center arena—the new home to the Brooklyn Nets—has donated to his cousin in-law’s opponent’s campaign. In fact, according to FEC filings, as many as 19 members of the extended Ratner clan have poured close to $80,000 into Brown’s reelect.

Michael, the former head of the Center for Constitutional Rights, says Mandel might’ve picked up some support if he were moderate, but he finds his in-law’s views simply “outside the framework of what we consider to be good for people.” (Mandel is a global warming-skeptic and rabidly pro-life; he supported an Ohio bill that would ban abortion if a fetal heartbeat is detectable.)

Not every Ratner is against Josh. Albert, one of the only Republicans in the family, and a co-chairman emeritus at Forest City, has, with his wife, chipped in $30,000 to Mandel’s PAC. And despite their mostly liberal leanings, this is not the first time a family member has run for the other party. When cousin Ruth Miller ran for congress as a Republican (and lost) in 1980, some supportive family members snuck “in the back door” to help her, says Ellen Ratner, Michael and Bruce’s sister. “We love my cousin Ruthie, we just didn’t agree with her,” Ellen explained.

But whatever the familial divisions, in the end, the Ratners’ opposition will make little difference in a race that’s been flooded with cash from outside groups like Karl Rove’s Crossroads GPS and the Democrats’ Senate Majority PAC. The projected total spending on television, cable, and radio advertising, on both campaigns, will be roughly $48 million dollars (about $29 million going to Mandel). Excluding outside spending, the money raised by the candidates alone ($15 million for Brown and $9.9 million for Mandel), makes Ohio the third most expensive Senate race, after Massachusetts and Texas, according to Open Secrets.

But Mandel’s quiet family defection does underline a problem that he, and Republicans generally, will have with Jewish voters in November. The GOP has made a huge effort to woo these voters. As the New York Times reported recently, the Republican Jewish Coalition has spent $6.5 million on a grassroots, social media, and television campaign to target Jewish voters in Ohio, Pennsylvania, and Florida. And there’s been a concerted national effort to cast doubt over Democratic support of Israel; Democrats recently reinserted language into their party platform asserting Jerusalem as the capital of Israel after Republicans jumped on them for the omission.

Despite this push, Jewish voters seem largely unconvinced. A Public Religion Research Institute survey earlier this year found that only 4 percent of Jews vote based on Israel. And an (admittedly) unscientific poll from the Cleveland Jewish News shows 81 percent of their readers support Brown over Mandel. Ohio voters, like voters everywhere, seem much more concerned about the economy than about what’s going on in the Holy Land—which Sherrod has a good record on, anyway. As Princeton academic Aaron Miller—and a distant Ratner relative—put it to me in an e-mail “Ohio politics and Israel, you’re kidding right?”

Ultimately, Mandel’s success or failure will have less to do with his family or his attendance at shul, and more to do with what comes out of his mouth. “He dresses nice. He makes a nice appearance,” the politically active Jewish voter told me. “So … I think, what a nice young boy he is! And then, of course, he talks about some issues, and then I think ‘oy yoi yoi.”