It wasn't just Nelson's little goody, it was also the deal for unions on excise tax.
The one thing Dems need to understand is that while people want their goodies, they're very very quick to get angry if they think that perceived Dem constituencies (unions, people with dark complexions) are getting more goodies than they are. "Nebraska" doesn't fit cleanly into this model, but "Democratic senator" does.
More generally, it's the problem with small-bore incremental liberalism, as opposed to programs that are now universal like Social Security and Medicare. Without universality, it's always easy to make it seem like someone else (someone less deserving, of course) is getting the goodies making good programs unpopular.
