A second piece of evidence is the republican drive to increase income inequality. We are now in the greatest gap between the haves and have nots since the Great Depression era, http://www.pewresearch.org/fact-tank/2013/12/05/u-s-income-inequality-on-rise-for-decades-is-now-highest-since-1928/. By decreasing the earning and spending clout of the working/middle/poor class republicans are in effect marginalizing and dividing our previously formidable backstop to the wealthy and their never ending lust and greed for more and more profit. So not only are many of we citizens within the working class being denied our right to vote, we are also being denied a fair share of our labor rightly earned.
To top it off, republicans have passed a couple of laws that allow them unlimited funding of elections. https://www.washingtonpost.com/blogs/govbeat/wp/2014/08/28/study-citizens-united-elected-more-republicans/. So no more can an ordinary citizen participate in our political process in the one person one vote dynamic, we are instead inundated with ads through the media blinding us to all the possibilities of alternative choice. Political systems for nominating and electing are made complex so as popular vote no longer carries the weight of what a true democracy demands. Democracy is crumbling before our eyes and the result will be much fear and suffering from those of us who will not vote to keep republicans out of office.