Of course this is not a credible source. For one its from the Washington Post and even they put it as “according to those familiar with her thinking”.
In other words they used themselves as their own source because they think they are familiar with her thinking.
I doubt Sarah has a problem with the John Birch Society but there are other sponsors of CPAC that might give her pause.
Very well put... lefties are always “trying” to do our thinking for us, especially when it paints a picture more to their liking.