"Staunch proponent" means someone who strongly supports and advocates for a particular idea, cause, or belief. They are unwavering and dedicated in their support. Full definition
McDermott's description of Traditionism as an essentially unified perspective assumes the truth of Oden's position and thus does not function well as a description of the actual evangelical theological spectrum, in which those of us who emphasize the authority of the early Church often find ourselves just as much at odds with staunch proponents of the Reformation as with those who wish to relativize all traditional authorities. (firstthings.com)
CCSA and our members have long been staunch proponents of charter school accountability and we were excited to be part of the initiative's launch. (ccsa.org)
That is implicitly acknowledged by even the staunchest proponents of options. (inc.com)