After striking a conciliatory note for most of 2009, the National Federation of Independent Business is now opposing both the House and Senate Democrats' health care reform legislation.

"Small business can't support a proposal that does not address their No. 1 problem: the unsustainable cost of health care," said Susan Eckerly, senior vice president of the NFIB in a statement about the legislation Senate Majority Leader Harry Reid, D-Nev., unveiled last night.

Their opposition matters because the 350,000-member group has used its grassroots muscle in years past to oppose legislation, most memorably 15 years ago when it helped play a role in ending then President Clinton's plans for health care reform.

The NFIB joined with other business groups, including the U.S. Chamber of Commerce, to create a coalition called Employers For A Healthy Economy, which has committed to spending as much as $10 million on advertising criticizing the House Democrats plans for health reform.

The NFIB had been working much of this year with Democratic staff, mostly in the Senate, to offer input into the developing health care legislation, and therefore remained conciliatory. We will be watching to see what they do next. I couldn't immediately reach an NFIB official for comment.

Meanwhile my colleague Marilyn Serafini and I have a story in tomorrow's National Journal looking at the NFIB and other groups that will have to be reckoned with for a health care bill to reach President Obama's desk.