Being a frustrating Conservadem definitely worked out well for him, didn't it?
In 2013, at the age of 71, he will have served two terms as a U.S. Senator after two terms as Governor. Yeah, I think it worked out just fine.
Nelson is your average politician of the opposite party traditionally dominant in his or her state that occasionally becomes (Nelson was barely elected Governor the first time, and won his first successful Senate race by an inch, after losing the first time) really well liked and becomes that "one person" that does really well in the state that wouldn't normally do so. There are Republicans like that in Democratic states that crop up every once in awhile and vice versa.
Nelson was elected in 2006 with nearly 64% of the vote. What's changed since then to crash his approvals? Like Blanche Lincoln and other Conservadems, it's the irresistible urge to draw attention to themselves. Nelson was one of the Democrats that tried to gut portions of the Stimulus for no real apparent reason other than just for the sake of doing it, drawing a boatload of negative attention to himself, and then ended up in the exact same position for HCR.
He became hated by both sides and become unable to either keep his head down and go along with the party, or take a stand for what he believed in (for or against) and stand strong. Jay Rockefeller is a Senator in West Virginia, which doesn't have particularly fond feelings toward Obama nor his proposals, but was there any equivalent outrage over him supporting it? No, he kept his head down. So did a ton of other Democrats in middle of the road states, and if they did draw attention to themselves, they didn't try waffling and asking for deals, they took their stand and said to their constituents, "No, I'm voting for this because it's the right thing to do, no matter what, and now I'm going to educate you on why."
Voters may like it when Republicans in traditionally Democratic states go after attention and stand up to Republicans, but that's only because Democrats are alot more willing to cast their vote for the other side than Republicans are for Democrats. When people like Blanche Lincoln try it, it gets them hated on the right, hated on the left, and looking completely spineless, which is exactly what happened to Ben Nelson. He drew a crapton of attention to himself, refused to stick to any sort of principles whatsoever, and drew the ire of just about everyone.
He got this far because of luck and being Completely Unknown and/or Thoroughly Uninspiring Conservative Democrat #702. Now he has nowhere to go but retirement. (And once again, he's just lucky he's old enough to the point that it doesn't look like complete cowardice to do so, at this point.)
