Freshman Rep. Jared Polis (D-Colo.), who has long been critical of the surtax on the wealthy, which he worries could hit small businesses, spoke up in favor of the tax on insurance. His comments about union opposition to the tax struck some on the call as surprising. Big Labor may be opposed to it, he told his colleagues, but the unions support the Senate plan, which must mean that they'll go along with a bill that includes such a tax.
This is the inherent problem with endorsing any piece of flawed legislation. The second a group endorses (or tangentially endorses by not opposing) a bill, they lose basically all leverage they have to improve it. Congressional leadership does not make substantial changes to a bill to make members who have already agreed to the compromise happier. They already have their vote, and have no reason to give them anything extra.
The same thing happens with outside interest groups. While the pro-choice groups say they are against the bill, they will not score a vote on the health care bill as a vote against a women's right to choose. In the world of Washington, this is, in fact, an indirect endorsement. If the pro-choice groups were willing to score the bill, it would instantly make the bill un-passable until the abortion language were improved.
The simple truth is that, in Washington, you can't endorse, or even stop fighting, a bad bill and then expect Congress to improve it to your liking. When people say, “This bill is full of problems, but you should pass it and try to fix it later,” all that the leadership in Washington hears is, “The bill is good enough so you have zero reason to change it.” If a group says it is unwilling to oppose a bill no matter how terrible it gets, they are signaling to members of Congress they have no reason that they should not be ignored.