So who did cast the critical 60th vote for the Affordable Care Act, a k a "Obamacare"?

Facing a new election year, the GOP has an answer ready to go: U.S. Sen. Al Franken, the Minnesota Democrat whose 2008 recount victory over Republican Norm Coleman helped alter the balance of power in national politics.

With the rocky rollout of healthcare.gov, Minnesotans can expect to hear a lot about the symbolic 60th vote; for example, U.S. Rep. Michele Bachmann recently penned an opinion piece calling Franken "a leading cheerleader and the 60th vote for Obamacare."

But in a body of 100 senators, Franken is hardly the only contender for the distinction. Not to mention that in the end, the essential finishing touches of the health care law passed the Senate — thanks to some tricky legislative maneuvering — with a mere 56 votes, not 60.

So that voters can better assess the 60th vote claim (Franken prefers to call himself the "second senator from Minnesota"), some math history is in order.

As the disputed 2008 election headed for the courts, Senate Democrats were still two votes shy of a filibuster-proof 60-vote "supermajority." The late Pennsylvania Sen. Arlen Specter changed that in early 2009 by switching parties, becoming a Democrat. That gave the Democrats control of 59 votes, and sharpened the stakes in Minnesota's protracted recount.

Franken's final victory in July 2009 made it 60. But a month later, the health care bill's most ardent champion, Massachusetts' Ted Kennedy, died.

Kennedy's temporarily appointed replacement, Paul Kirk, could just as easily be considered the "60th vote." Or, just as plausibly, it was Connecticut independent Joe Lieberman, who held out until the controversial "public option" was jettisoned. Or perhaps more famously, the distinction could go to conservative Nebraska Democrat Ben Nelson, who held out for a Medicaid provision widely derided as the "Cornhusker Kickback."

Whoever takes the credit or the blame, the Senate approved the law in December 2009 on a vote of 60-39, the minimum necessary to avoid a GOP filibuster.

But the drama was far from over. In January 2010, Massachusetts voters elected Republican Scott Brown to fill Kennedy's seat. Suddenly, there was no more 60th vote.

The House, then still controlled by Democrats, hadn't voted on the bill. Any changes in the House version would send it back to the Senate, where the Democrats were back to 59 votes.

And to pass Obama's signature health care law, the White House still needed to win over centrist and conservative House Democrats with a long list of concerns about abortion funding and the Cornhusker Kickback.

To get around this, the House passed the underlying Senate bill, but only with the understanding that a separate bill would be crafted to address the remaining stumbling blocks. Since those issues were mainly related to taxes, subsidies and other money matters, the Senate was able to pass the second bill under a "budget reconciliation" rule that didn't require a supermajority. It passed, in March 2010, by a vote of 56-43.

So now perhaps the question should be: Who was the 51st vote? (Repeat until you get to 56.)

The week ahead

Congress returns this week from its holiday recess. The Senate will convene on Monday and the House on Tuesday.