The resolution was intended both to contradict President Trump, whose recent positions have been pro-occupation and pro-annexation, as well as to potentially warn Israeli Prime Minister Benjamin Netanyahu against any hasty annexations, something hes been advocating recently. The bill was hardly perfect, which meant a lot of the voting on the margins defied conventional wisdom. Some traditional critics of Israel voted against the bill over language, and still others rejected the bill because it proscribed a US-imposed solution.
The gang of four stood as four Democrats opposing the resolution, and did so because the bills final version removed any mention of settlements, of Israel being an occupying power, and watered down language about the two-state solution at the behest of more centrist Democrats.