http://www.breitbart.com/article.php?id=D95D7M180&show_article=1
The last time the Senate refused to seat a member was in 1947, when Mississippi Democrat Theodore Bilbo was accused of corruption and bribery, according to Don Ritchie, associate Senate historian.
There was one in the 70s to.
Re#10 Thanks for the link. Coincidentally, the 1969 Powell case I was thinking of just showed up here: http://www.freerepublic.com/focus/f-news/2156293/posts