Because despite appearances that are put on, the main bulk of republicans and democrats are really not very far apart. A show is created around culture war which is really not particularly cared about by either of them while the core interests that they both share - exploiting the people and maintaining the class war in favour of the bankers, hedgefunds and financial elite - are ultimately kept secure.
Until the well-meaning liberals that continually give the benefit of the doubt to democrats wise up to this and radicalise into something further left the lack of opposition to the right will continue. Meanwhile the few dedicated and ideologically motivated actual-fascists that do get power, such as in Florida, will get to wield that power however the fuck they want as long as it isn't affecting the economic interests of the previously mentioned groups belonging to the wealthy ruling class.
An enormous amount of power exists to prevent or oppose all the things that have been happening lately. The issue is ultimately an unwillingness to do it.