Which counties are most important in the Third Congressional District?

Here are the vote counts for each county in the 3rd CD in the 2014 Republican Primary:

County	Total
Carroll	7,205
Coweta	8,480
Fayette	10,138
Harris	2,588
Heard	953
Henry	2,864
Lamar	1,289
Meriwether	1,081
Muscogee	4,477
Pike	2,087
Spalding	4,741
Troup	4,642
Upson	2,855
Total:	53,400