As government has grown we have become a government of the bureaucrats, for the bureaucrats, and by the bureaucrats.
They run every service. Even back in the 1940's president Harry Truman described being president like being in charge of a 500 square mile sponge. He could hit it has hard as he could and nothing more than 3 feet away even felt it. When the boss is temporary it is hard to make the help do what the boss says.
Staffers in congress stay employed for their entire career. This term they will work for one member. If that member loses the will work for another member. If there is no congress person to work for, they go to work in a government agency. They are the ones that put words in our elected officials mouths. They run the show.
You can see it in people like Pelosi. Today staffer A tells her what to say. So she says A... Tomorrow staffer B is on duty so she says B. Pelosi does not even know that saying B contradicts A.
The more turnover in elected officials the more the bureaucrats can pull the wool over elected officials heads.
The fallacy is that our laws are written by and our government is run by elected officials. The truth is more and more our nation is run by unelected and unknown bureaucrats. By the time a congressperson is able to pull the wool off his eyes his term is up. We fire him at the polls and elect a new congress-critter. Then the bureaucrats get to fool the new sucker until we fire him.
We elect people and then blame them. We never figure out that they are not running the show. Most elected officials don't even know what show is playing. They have to ask a bureaucrat.