I don't think the Democratic party actually had a supermajority. January of 2009 there were 57 dem senators plus Bernie and Lieberman (who refused to vote for single payer); however, Al Franken wasn't sworn in until July because he barely won the election and Republicans forced a recount, leaving that Senate seat empty. Ted Kennedy was dying and stopped showing up in March and later died, Scott Brown (a Republican) won that seat in a special election. Kennedy did have a replacement who voted in favor of ACA right before Brown won his election.
I don't believe there was ever a time where dems actually had 60 votes in the Senate during 2009 except the pretty short period where they did manage to pass the ACA with exactly 60 votes that included Bernie, Lieberman, Franken, and Kennedy's temporary replacement. But remember that Franken wasn't there until July and Scott Brown got elected right after ACA passed the Senate in December 2009. So by the time the ACA made it to the House vote it was March 2010 and if the House Dems didn't pass it as it was, the Republicans would be able to block it in the Senate.
I'm not so sure that Dems would have done more if they had a proper supermajority, probably not
I just play unciv instead now