Washington (CNN) - Health care reform is a signature issue for Democrats, but the attempt to overhaul the nation's health system has pitted liberals against centrists, exposing fissures 11 months before the 2010 midterm elections.
A year ago Democrats were united in victory after winning back the White House and picking up additional seats in Congress. But with victory comes expectations that are accentuated when a party controls both ends of Pennsylvania Avenue.
For Democrats, it is the party's political base - voters who turned out in 2008 to help elect Barack Obama president and boost the Democratic majorities in the House and Senate - which is demanding results.
Simply by the numbers, the health care overhaul should easily pass Congress. Democrats comfortably control the House of Representatives, and with the assistance of two Democratic-allied independents have the 60 votes needed to overcome a Republican filibuster in the Senate.
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Except it is not about numbers on health care. It is about differences in ideology on the public option and abortion that has slowed down the bill.