Likewise, who decides if the judicial branch has rendered decisions which are inconsistent with the Constitution? It's turtles all the way down: the legislatur

Likewise, who decides if the judicial branch has rendered decisions which are inconsistent with the Constitution? It's turtles all the way down: the legislature's laws are reviewed by judges or ignored by the executive; judges & members of the executive branch may be impeached by the legislature; ultimately the voters decide what they're willing to let their government get away with.