There is precedent and it's been done before. The most famous case was arch-segregationist George Wallace. He had his wife run as Alabama governor to bypass Alabama's constitutional term limits.

There's really no way to prevent this Constitutionally. A core principle of democracy is that voters can elect someone who promises to follow any style of leadership they want. There are limits on what power the leaders have, but they can make their choices however they want. You could run for president promising to make all your decisions by literally pulling options out of a hat at random. You could run for president promising to literally never even do the job. You could tell voters you're going to take the oath of office and immediately go back to your home, close the door, and never walk out again for the next four years. Just let the government run on auto-pilot. You probably wouldn't win an election on either of those, but it would be perfectly Constitutional for someone to do either of those things. There's language in the Constitution about the President faithfully enforcing the laws, but the only enforcement mechanism is impeachment and removal.

It would be nearly impossible to even write a Constitutional amendment prohibiting this. Leaders are allowed to take advice from their advisors. They couldn't govern without advisors. In this case, the person holding the seat just has one advisor they really really trust and listen to on everything.