alt Hacker NewsIf a suitably-sized majority wants to amend the constitution (where "suitably sized" is defined by the constitutional amendment process), they can go ahead, always. That's why to some degree this is just pushing the issue of "tyranny of the majority" out one level - but that doesn't mean it is not worthwhile.
On the other hand, electing leaders who simply decide to not follow the constitution (perhaps because they believe they have "a majority" at their backs, or perhaps not) is something entirely different.
My point is that having a majority that isn't large enough to amend the constitution is far more common than having a supermajority aligned on an issue at any given time, and there's still plenty of danger from that majority trying to erode the protections in the constitution without amending it. There hasn't really been any serious attempt at writing a new amendment to the constitution at least since the ERA was sent to the states from Congress over half a century ago despite a fairly noticeable trend of increased executive power in the same time period (after a brief dip in the immediate aftermath of Nixon). In fact Nixon getting elected in 1972 (the same year as the ERA getting passed in Congress) is the last time any presidential candidate got even 60% of the popular vote, which is still below the threshold that would be needed for a constitutional amendment, and no one has gotten even 54% percent of the vote in the past four decades. If you're trying to argue that no majority-elected president since Reagan has had any incentive at all to try to push their power beyond that specified in the constitution, then I guess that this wouldn't be a concern to you, but I don't think it's a particularly controversial take for me to argue that there has been ample incentive for at least some of these presidents to try to increase their power.