Obamacare was never supposed to be a winning issue for them. You can tell by the schedule. Anytime a president hammers through something that won’t start going into effect until after his re-election bid and won’t finish until after the second term is over he knows it’s going to be unpopular.
The schedule was driven by political timing, sure. However, they expected by this election cycle to be hitting the GOP hard over their support for the private sector by pointing out how the insurance companies are screwing everyone. Their positive was going to be the rescue of single-payer.
It's not that Obamacare was ever going to be a positive, it was just meant to be a winning issue... they could use it against their enemies as a club and ride in on white, single-payer horses to rescue the downtrodden. Their implementation took away the club and has made the second more difficult (though not impossible).