Earlier quoted context omitted.
Gerrymandering has no effect on the Senate or Presidency making this largely a non sequitur. Furthermore, administrators of independent agencies (such as the EPA) need to confirmed by the Senate. Up until 2013, appointees could be blocked by a minority with a filibuster. That rule was changed in 2013 by a Democrat majority Senate under Obama, to make it such that a simple majority could force through any appointee. T…
This is true in a world of balanced power between Congress, the judiciary, and the executive. It is not true anymore, as all power is centralized in the parties. The House’s impeachment power will essentially never be used against the dominant party’s President, which allows POTUS to act with impunity and strongly incentivizes him to secure his party’s House dominance — a dynamic we’re seeing very explicitly at play…
For the normal balance of powers - the legislative makes laws, the executive implements them, and the judiciary ensures the latter matches the intent of the former as well as that they remain constitutional. The legislative can undermine the judiciary or the executive by passing new laws. The executive can undermine the legislative with vetos, and the judiciary by appointments. And the judiciary can undermine the legislative by deeming the laws unconstitutional, or the executive by deeming their enforcement unlawful.
No branch is particularly superior to the others. The executive has the strength of being headed by a single person, but that is tempered by it having relatively less power than the other branches.