ALBANY—For liberals, this was the year of great expectations. It was the first time in three-quarters of a century that Democrats controlled all three governmental levers in Albany, and the newly empowered Senate Democrats, led by Malcolm Smith, talked about legalizing same-sex marriage; passing new laws to protect tenants and mandate prevailing wages on public projects; and creating a new governmental process to make the Legislature transparent and decentralized. Of course, it all started to go wrong pretty quickly. Four holdout Democratic senators first refused to support Mr. Smith for majority leader, then three of them continued to act in concert to frustrate the conference’s ability to deliver on just about anything.