The National Association of Medicaid Directors opposes the Senate health care bill, saying the cuts it makes to the program are too deep. NAMD represents all 56 Medicaid directors, and the decision to oppose the bill was made by its bipartisan board.

The spending growth rates for the proposed Medicaid per capita caps are "insufficient and unworkable," the directors wrote in a statement to be released Monday. While they say they support some elements included in the bill, "no amount of administrative or regulatory flexibility can compensate for the federal spending reductions that would occur as a result of this bill."

Why it matters: Coming after GOP Sen. Dean Heller of Nevada said he opposes the bill, the statement is an indication that the Medicaid cutbacks are now one of the biggest threats to the bill's passage.