© Baltimore Sun 2009 

Senate Democrats, facing stiff Republican opposition, were forced Tuesday to delay votes on the first set of amendments to the gargantuan healthcare bill underscoring the fiercely partisan nature of the floor debate and threatening Democrats' tight timeline for achieving final passage.

Party leaders, scrambling to pass a bill by Christmas, had hoped to be able to approve a proposal Tuesday designed to expand women's access to preventive services such as mammograms, a provision favored by leading advocacy groups for cancer patients.

But instead, lawmakers spent much of the day tussling over the healthcare bill's potential impact on the 44-year-old federal Medicare program for seniors, a debate that has shadowed the healthcare legislation for months. Read more.