You mean the way society is run right now?
Well, you're close. American "capitalism" grafts elements of mercantilism and welfarism, and their democracy is also a republic :P
By adopting a new ideology, I mean that the public conscious will adopt and adhere to an ideology faster than they usually do. This happens either when the ideology looks to make changes, or when it looks to divert from the real problems, give something to rally around, justify its adherents, etc. So at certain times, a society will change its views on something for one reason or another. This can be a good thing, like how several ideological shifts helped turn black Americans from slaves into legal equals. Or it can be people clinging to something they can believe in because shit's getting tough: observe Roms adopting Christianity as it went down the shitter, Han China adopting Buddhism. Both of which were fairly harmless by the standards of the time, although Christians did persecute other faiths later on. But hey, a lot of Greeks are finding neo-Nazism appealing because their country is having a tough time, and that's probably not a good thing!
So I'm thinking that the spread of Evangelical Christianity and of social justice theory are both new ideologies pretending to answer people's questions about the world (with the caveat that evangelical Christians are building on the work of much older Christian factions- I'd say that they're "new" due to the fact that its current form is a fairly recent phenomenon). Having more historical momentum, I consider social justice theory to be more harmful. Everyone knows that evangelicals are living in the past, but SJW's have had more luck slipping under the radar.