Comment by Teocali

You forgot all the votes you need to win to be able to cast your first vote. It’s not easy part, at least in a more-or-less healthy democracy.

In France, for exemple, you need first to have majority in both chambers (Senate and parliament) to validate the content of the modification. Then you need to have of 3/5 of parliament OR the majority in a referendum for apr roving the modification and putting it in the constitution.

And for almost every healthy constitutional democracy, it the same order of difficulty.