For years I was actually registered Republican here in Kansas so I could vote for moderates in the primaries. However, since Brownback has purged almost all the moderates, there is no point in it. I am too pragmatic to register third party. Like it or not, in the USA, we have 2 parties: Republican and Democratic. Once in a great while an independent gets elected, but 99.9% of the time, your choice is either a Republican or a Democrat.
One might argue that since Kansas is such a red state, someone that might would vote Democrat could just register with the Green Party and support them, but from a practical standpoint, they will never win anything here, so I would rather support a Moderate Republican Candidate in a state or local election that I might agree with half the time, then throw away my vote on some Green or Libertarian Candidate and the moderate candidate lose to some total nutjob on the far right.