As an external observer, I notice that in the pending US Presidential election a lot of voters don't like and don't feel represented by any of the candidates. The feeling is that the games were made during the primaries, the results of which are marred by suspects of rigging. This is nothing new, also some earlier elections including the one which saw Trump against Clinton went on in a similar context.
At the same time, voter turnout is low and with this mood it is not likely to grow.
Could introducing a two round voting system for all elections (Presidential, Governorship, House, Senate and so on) help reduce the problem? By "two round voting" I mean something similar to the system in France and many other countries. The first round is not a primary, but an official election, this allows the participation of many parties, there could be no room for accusations like the ones made to Nader of undermining the Democratic Party candidate. This would not rule out the usual primaries happening in every party, but also would not leave the voters with a very restricted choice at election time.
My assumption is that more parties would be likely to participate at the first turn, not only this would allow more voters to find a candidate whose view they can identify with, but all the parties would have to handle carefully their primaries otherwise their candidates wouldn't pass the first turn.