Excommunication no barrier to being a Templar

If you want to get an idea on why the Templars may have made quite a few enemies early on, then their acceptance of excommunicated men in to the Order is a good starting point.  Some early sources say that the Order had to gain the permission of a local bishop to allow somebody who had been cast out of the church to become a Templar.  But even that requirement seems to have been junked as the Order blithely informed the “established” church that it answered only to the Pope.  So…it could admit anybody it wanted so long as the Holy Father, in far off Rome, didn’t raise any objections.  In the context of medieval Christendom, that does seem quite extraordinary.  It must have been angered and confused many prelates to see the Temple recruiting people who, one assumes for good reason, had been forbidden the holy sacraments and shut out from the Catholic church.  Yet it seems they could knock on the door at their local Templar preceptory and next thing, they were off to the crusades.  How did the Templars get away with this?