The Senate moderates who helped keep the Democrats' health care bill alive yesterday are warning that they could scuttle the bill if their demands are ignored.

In what could be a preview of the Senate floor debate to come, senators have been airing their differences on the Sunday interview shows.

Sen. Ben Nelson of Nebraska tells ABC he wants tougher restrictions on what taxpayer money will fund.

More liberal Democrats are sounding annoyed. Ohio's Sen. Sherrod Brown tells CNN he doesn't want "four Democratic senators dictating to the other 56."

Illinois Sen. Dick Durbin tells NBC there's a clock ticking. The Senate's No. 2 Democrat says a health care bill must be passed by the end of the year. By that point, he says President Barack Obama and Congress will need to shift their attention to the economy and jobs.

On the Republican side, Sen. Lamar Alexander of Tennessee tells Fox he thinks the measure will collapse under its own weight during the debate. On NBC, Texas Sen. Kay Bailey Hutchison of Texas calls the Senate measure "a disaster" for the nation.