In terms of ObamaCare, his rulings have attacked pro-life Christians, the largest body and most consistent over time of which has been the Catholic Church.
But you're making the "toothless tiger" argument. While the RCC has been very vocal in their defense of the unborn, their church membership has consistently voted for the people who passed the laws that allow the unborn to be killed. In addition to that this membership consistently voted for the politicians that subsidized planned parenthood and other abortion mills. Compare this record with the voting record of the less publicized, decentralized Evangelical Christian community. I'm always more impressed by the 7 day a week Christians rather than the Sunday go to meeting Christians.
I agree with your analysis of obamacare. It is a direct assault on pro-life Christians. As we see all Christian values denigrated and mocked we are seeing the end of American Exceptionalism. Religious liberty is coming to an end. The assault on churches will continue until church membership is what it is in Europe, something you're born into and doesn't mean anything else.