Here's an outline on his PLO background and association with Barack Obama from his Wikipedia page.
Khalidi has been accused of having ties to the Palestinian
Liberation Organization, based on his work for Wafa in the late 1980s. Khalidi has
been accused of being “a director of the Palestinian press agency,” publishing
an "adulatory book" on the PLO in which he personally thanked Yasser
Arafat, and acting as an advisor to the Palestinian delegation during peace
Khalidi denied the allegation that he served as a PLO spokesman.
Khalidi explained that he often spoke to journalists in Beirut, and was usually
cited, without attribution, as a well-informed Palestinian source. He also said
that he was unaware of any misidentification as a PLO spokesman.
How has Khalidi come to be relevant to Barack Obama?
The claim received renewed attention in 2008 when it was raised due to a
reported friendship between Democratic presidential candidate Barack
Obama and Khalidi's family when Khalidi taught at the University of Chicago.
Articles by Aaron Klein and John Bachelor, writers respectively for conservative outlets World Net Daily and Human Events, were referenced by rival political campaigns and reprinted in wider-circulation media.
A recent Associated Press profile on the Obamafia had a section on Khalidi, but left out the alleged position as spokesman for the PLO.
RASHID KHALIDI: Khalidi is a scholar and author on Middle Eastern affairs
who has criticized Israeli policies and was part of a Palestinian advisory panel
to peace talks in the early 1990s. He's also a friend of Obama. They met while both were teaching at the University of Chicago and living in the same neighborhood. Obama and his wife sometimes had dinner with Khalidi and his wife, Mona. The Khalidis hosted a political fundraiser for Obama in 2000, and the Woods Fund charity gave money to the Arab-American Action Network, run by Mona Khalidi, while Obama served on the charity's board.
Khalidi and Obama have both said they hold very different opinions on Israeli issues, but their friendship has been used to raise questions about Obama's support for Israel — and to generate Internet headlines such as "Meet Obama's Terrorist