> The check on tyranny of the majority, beyond notional defense of rights, is that the representation of the House vs the Senate differ from each other and so agreement between them (and especially a durable agreement between them) probably means more than "mere" majority support.
The problem with this theory is that while they differ, they don't have opposing bias (and the electoral college combines their biases, so the bias in the Presidency also doesn't oppose the electoral bias of either House or Senate. Which is why (with the present ideological configuration of the parties) Republicans outperform their popular vote share in the House, and the Senate, and the Electoral College; aligned bias does not inhibit total domination by the majority, it enables it (or even domination by the minority) in the direction of the bias.
Now, ignoring the aligned bias in those institutions, one thing that works against dominance by a transiently electorally advantaged faction is the electoral calendar. While the House is elected every two years and the Presidendy every four, only 1/3 of the Senate turns is chosen every two years.
The “good behavior” tenure of federal judges and the high Constitutional bar for removal (2/3 of the Senate) also serves this purpose ideally, though it has a failure mode that can instead increase the reach of a transitory political dominance, depending on timing of appointments.