I can respect someone who honestly doesn't believe it will work. But I think they're wrong. Conservatives regularly make the argument "it just won't work in the US, we're too big" (despite countries like Sweden having vast swathes of frozen wasteland). But you know what? Colorado is about the size of any given European country, and with a strong tech economy. I want to see what happens. Worst case scenario, we can repeal it if it explodes, and the only thing lost is some spending money from a few well-to-do middle class people like myself who can spare it.
But, practicality notwithstanding, as a Christian, I'll almost always vote for social things. I believe Jesus' #1 physical ministry was to the poor. I don't have to tell you, there are countless verses in both the Old and New Testaments commanding helping the poor. And some pretty dire consequences for not doing it in Matthew 25.
When I lived in Texas, most of the Conservative Christians I knew used the argument, "It's not the government's job, it's the church's job." You know what? The church isn't doing its job. And at the end of the day, I don't care who does it, as long as it gets done.