From the Jerusalem Post 

The US Internet news portal, Breitbart news is offering a $50,000 reward to  anyone who can provide the videotape of a 2003 dinner honoring a radical  Palestinian American academic attended by then Illinois state senator Barack  Obama.

Obama has acknowledged  a close, long-term friendship between his family and the Khalidi family. Khalidi  and his wife Mona, who served as the editor of the PLO’s English news service in  Beirut from 1976-1982, hosted a fundraiser for Obama’s failed Congressional  campaign in 2000.
According to the Times report, at the 2003 dinner,  Khalidi told his Palestinian American guests to support Obama’s 2004 bid for the  US Senate. According to the report Khalidi said, “You will not have a better  senator under any circumstances.”
During Obama’s tenure as a director on  the board of the Woods Fund of Chicago, the charitable group donated $75,000 to  Khalidi’s Arab American Action Network.
The Times article notes the  virulently anti-Israel discussion that took place at the 2003 Khalidi dinner.  Among other things, a Palestinian read a poem accusing Israel’s government of  terrorism and sharply criticizing US support for Israel. The speaker reportedly  threatened Israel saying that if Palestinian interests are not secured, “then  you [Israel] will never see a day of peace.”