A tiny fraction of republicans even go to state conventions where national committeemen are chosen. There were only some 1500 total votes case at the convention in Michigan but a small group of tea partiers, GOP conservatives, and even Paul voters got together and removed uber RINO Saul Anuzis from his national committee seat and replaced him with conservative Dave Agema.
http://www.commerce.gov/sites/default/files/images/2010/december/totalpopulationbyage2010.jpg This is a line graph showing population by age in 5 year increments. Notice that the Baby Boomer Bulge is already flattened and on its way downhill! That’s the missing voters.