Gary,  I don't think real change can happen by reforming from within.  At best it leads to incrementalism and divides The People and pits interest/constituent groups against one and another which is what we have today.  And you are right, as the pie shrinks or as the national debt inevitably expands, it gets worse.  So what instruments can bring significant change:

a) The best and quickest; an individual such as Theodore Roosevelt accidentally rises thru a party and with the support of The People brings real change.

b) The most disorienting and likely to fail. The People decide enough! I'm not supporting this party anymore and begin to abandon it for a probable charlatan.  I believe this is what is going on with the republican party now.  Trump isn't a republican, he is a reactionary populist that surprised even himself with the republican nomination.  And like Robert Redford's character states in the final scene of the movie, "The Candidate", "What do I do know?"