This does not accord with the Israeli experience. The Haredim have grown enough as a proportion that they shifted the Israeli median voter substantially to the right.
Haredim “get away” with minimizing participation in many ways, which makes their attrition rates lower than comparable religious groups. But that doesn’t last forever; compare the secularization of Jews in Austro-Hungary in the late 19th century.
But that was implied by discussing a carrying _limit_ right?