The Washington Post has one story on the turmoil Feingold's proposal has caused among Democrats who are, apparently, can't quite grasp the notion of a member of their party in the Senate actually taking a stand based on principle.
Here's a bit of background on the Wisconsin Senator, from the Washington Post:
While other Democrats speak more colorfully, or show up more often on television, Feingold has carved a niche as one of the least-predictable senators. As he contemplates a presidential bid, Feingold is emerging as an anti-establishment maverick, a blend of Howard Dean, John McCain and the late Wisconsin progressive senator William Proxmire.Feingold was the only member of the Senate to vote against passage of the original Patriot Act. Unlike his colleagues, he probably read the bill.
The Rhodes scholar and Harvard Law School graduate was elected at age 29 to the Wisconsin legislature, defeating an incumbent by a handful of votes. He turned back two better-known Democratic challengers in the 1992 Senate primary by ignoring their mudslinging and running humorous ads, including one in which he conducted a tour of his Madison area home, noting the closet space and saying, "Look, no skeletons."
Feingold has shown little of that humor in the Senate. He rarely engages in small talk with colleagues and is so unpredictable that fellow Democrats rarely seek his help in legislative battles or include him in public events. He irritated many colleagues in his long crusade for campaign finance reform, which Democrats feared would put them at a fundraising disadvantage; by his opposition to dropping all charges against President Bill Clinton during impeachment proceedings; and with his support for the confirmation of Chief Justice John G. Roberts Jr.
But it is Feingold's national security views that have stirred the most controversy, vaulting him into the national spotlight. Before the censure bid, he was the first Senate Democrat to call for a troop withdrawal from Iraq, and he waged a solo filibuster against the renewal of the USA Patriot Act.
Democrats in the Senate are responding with typical courage.
A party not willing or able to defend, protect and uphold the Constitution and laws of the United States is not capable of leading this country. That applies to Republicans as well as Democrats.
UPDATE: Actually, William Greider, writing in The Nation, makes this case much better than I do.