It may be defined as legitimate, but that doesn't mean it feels like it.
"Whaddya gonna do? Boss says so."
For anyone who has felt like they had no other option than to do what the boss said, because they were boss, was observing legitimate power.
French and Raven describe legitimate power as being derived from a person who has a formal right to have power in the form of making demands and have the expectation of others to comply and obey.
Who has legitimate power?
bosses
police
first responders
healthcare providers
legislators
investors
teachers
parents
Anyone who one might consider as being 'in charge' likely has legitimate power.
What does this mean to us on a daily basis?
Generally and broadly, society gives people legitimate power in order to respond to needs and crises. For example, a person standing around in a big concert venue is just a person. When they have a shirt that has "SECURITY" printed on the back, that same person now has legitimate power. If one does not observe their directive, it is possible the unobservant individual will be required to enjoy themselves outside the venue.
There's some real need here. Without having safety and security in place people might have significant needs not met and have serious repercussions. There may also be what our legal friends might refer to "bad actors" who intend to do bad things. People responsible for retaining safety and security are needed and it is necessary to give them a title to communicate this legitimate power to accomplish the needed outcomes.
Now that "bad actors" have been introduced, what if the bad actor also has legitimate power? Can you think of any bad actors who had legitimate power? Without being overly cynical, one could review the small sample of titles provided above and come up with some concrete examples of bad actors who held titles in those areas.
The psychology of leadership and followership is deep, wide, and outside the scope of this discussion. At the same time, one can imagine how a person with legitimate power can convince someone else to do something that they probably would never do otherwise.
If, at this point, you're saying this would never happen to you, please continue reading.
This is not the part where a convoluted hypothetical is introduced to force you into an impossible decision where the only reasonable outcome is doing what you might not otherwise do. Please consider all of the stories you've read and documentaries you've watched about bad actors with legitimate power. The people they've taken advantage of frequently seem like level-headed people. "They told me to [take action] and it seemed weird to me, but they're the expert so it didn't seem right to argue."
People who are in positions with legitimate power may not be bad actors, but still lead people to a less-than-wonderful space. The leader knows what they want to accomplish and feel it's the right place to be. Thus they make their choices, and sometimes, don't care too much about the means to get there. Along the way, there's bending of rules and jostling of ethics. People go along because, "Well, after all, it's not so bad, I see where they're going with this and, at the end of the day, they're in charge."
A reasonable conclusion now is that legitimate power is a difficult one to navigate. For a person in power, making a recommendation or stating an opinion can be easily confused by many listeners with a declaration or directive. For people depending on those with legitimate power, there's a giving of power to the leader with the expectation that they have everyone's best interest in mind.
People in positions with legitimate power need to be able to tell the difference among circumstances when that power is needed and when it is simply available. A lawyer arguing relentlessly for her client in court; seems okay. A lawyer arguing relentlessly for his client with the waiter who brought the wrong order; seems out of place. Legitimate power is one that can be left behind and may be "taken off" like a uniform, nametag, or hat. Although, even when removing the visual trappings of a person with legitimate power, people will often still observe the residual power.
For those who do not have roles that come packaged with legitimate power, that doesn't mean you're without power. If given direction or a directive within the scope of your job, it's best to follow through. If given direction or a directive outside the scope of your job, asking questions about that is a good idea. If given direction or a directive that is more likely than not to land you in court or jail, it's a good idea to not do it and possibly report it to someone else with legitimate power who is capable of taking action (or at least starting the process).
Power comes in different packages and is seen different ways. Many organized societies rely on legitimate power. The intent is to ensure agreement about who has what authority to achieve what outcomes. The unfortunate byproduct can be corruption or abuse of power. Actual and authentic leaders with legitimate power will set the tone for the best possible outcomes for those they serve.
Source: https://www.mindtools.com/pages/article/newLDR_56.htm