John (The Traitor) McCain would clearly go public against a Janice Rogers Brown. He won't go against Miers even if he thinks she is a closet conservative because he would have no evidence to support that theory and end up with egg on his face.
As for why these Rinos exist, it is unfortunate but in the Northeast, we either get Rinos, or Democrats. Real conservatives are tarred and feathered in the primaries.
We have to live with that and either bolster the South, the Southwest, and the Midwest with real conservatives. Getting rid of Rinos in the short term would only make us a minority.
That's cause you lazy Northeastern conservatives aren't pulling your weight ;-)
I'm in MA. Conservatives are tarred and feathered by the State party, every obstacle is put in their path, and the party's harder on them than the Dems.