Yes there is. You need the entire country for national elections and there is one government from one parliament. You might have the same on state level, where interference is easier. But you need thousands of judges in thousands of districts. That will become very easy to interfere with.
But a corrupted muncipal parliament does not have the saem effect, like a corrupted judge, who can let his buddies off free, while imprisoning journalists and other critical dissidents against the cartels.
If most counties are like 53-47, 55-45, maybe even 65-35, having one county where it is like 90-10 will be dead obvious manipulation.