Despite all this, Democrats
could not pass the law through normal parliamentary procedures. The election of Republican Scott Brown of Massachusetts to the seat left vacant by Sen. Ted Kennedy’s death ensured that. Brown explicitly ran on a platform of stopping the Obamacare train wreck, and his election gave Senate Republicans the 41 votes they needed to filibuster the law.
The only way for Democrats to avoid the filibuster was for the House to pass the Senate version exactly as written to
avoid another Senate vote. However, opposition to the Senate version ran so deep in the House that Democrats
had to cut an eleventh-hour deal promising pro-life Democrats that the law’s abortion-related provisions would be eliminated through a procedure called reconciliation. Under it, the House appended the pro-life revisions to
an unrelated bill the Senate had already passed — one it could approve by a
simple majority vote. (
source)