Until the election of 1852, everybody understood that only a Whig or a Democrat could be elected. The Whigs, however, were unable to find consensus on the issue of slavery; and their house, divided against itself, could not stand. A similar thing is happening now with the Democrats around the issue of oligarchy – and it might spell the end of the party.
FDR made a fatal error when he backed off of anti-lynching legislation to appease Southern Democrats. Today’s progressives can make a new, stronger coalition that isn’t tainted by racism.