Sanders is particularly worried about a proposed provision that would nullify existing state programs to limit emissions. Vermont is among those states that have paved the way for national carbon regulations, and the bill would remove the ability of states to set tougher restrictions on carbon dioxide than those passed by the federal government. Sanders describes this as "a huge mistake," writing that "we should definitely set a floor, but not a ceiling." He also expresses reservations about new loan guarantees for nuclear power, expanded offshore drilling, and the bill's likely giveaways to coal. "I do not want to see a global warming bill become an bonanza for the coal industry," he writes.
Sanders is also worried about what's not in the outline of the bill that the senators are circulating. In particular, he thinks that their plan doesn't do enough to promote energy efficiency, develop a renewable energy industry, and provide incentives for green jobs.
At the end of the article, Joe Lieberman brushes off the threat of any left-wing revolt on the bill, stating that Senators will fall in line as long as the bill is viewed as an improvement on the status quo, however minor.
A Lieberman versus Sanders conflict is particularly notable, as history tells us there are reasons to respect threats from both Senators:
Given recent history, there is good reason to suspect that left-wing Democratic members of Congress will simply fold and support a bill that is a marginal improvement on the status quo. Then again, there are some members of the Senate, most notably Bernie Sanders and Russ Feingold, who have frequently proven themselves unwilling to fold without at least receiving some sort of important concession.
To put it a different way, there would be every reason to not take left-wing criticisms of the climate bill seriously if they were coming from almost anyone in the Senate except Bernie Sanders.