A California Senate candidate is on the defensive over his involvement nearly a decade ago with a radical Muslim professor.
A 2002 letter written by former Republican Congressman Tom Campbell appears to differ with his prior account of his relationship with Sami Al-Arian.
Campbell says he is the target of a "whispering campaign" questioning his commitment to Israel.
In 2001 Al-Arian was in danger of losing his job at the University of South Florida after acknowledging he called for the destruction of Israel.
Campbell received a $1,300 campaign contribution from Al-Arian in 2000 and in January 2002 wrote a letter asking the university not to fire him.
But the date on the letter is months later than Campbell and his campaign had said it was written.
Al-Arian pleaded guilty in 2005 to aiding a Palestinian terrorist group.