[jltsiren]

The broken part is the idea that the legislative and judicial branches can act as checks and balances for the executive branch. In the end, the executive branch is the only branch with the ability to do something. The other two are just a bunch of talking heads.

Many other republics have split the executive branch into multiple semi-independent centers of power. The head of state and the head of government can be separate roles. A directly elected president may be responsible for signing laws and appointing senior officials, while a prime minister subordinate to the parliament may be in charge of running the executive branch. And government departments may have dual leadership with a politically appointed minister setting the directions and a career director appointed by the president running the department. Because the director's term is independent from the political appointees, they can refuse to comply if the minister asks something illegal.

Republics have all kinds of failure modes. For example, Hungary was supposed to be a robust parliamentary republic. But due to non-proportional elections, slightly over 50% of votes were enough for a sufficient supermajority to rewrite the constitution.