Is there any idiom for a person who somehow obtained a (usually small) power to control people and is using it in every possible way to make problems for people around him?
I don't know how current or widespread this is but one term is 'a little Hitler'. Google ngram: a little Hitler
As the produce of an evident inability to make moral distinctions, Chorover' s verdict shares with such seemingly innocuous and self- deprecatory confessions as "there is a little Hitler in each of us,"
Race and Other Misadventures: Essays in Honor of Ashley Montagu By Larry T. Reynolds, Leonard Lieberman
A term that is probably restricted to Britain but very widely used here is 'a jobsworth'
A jobsworth is a person who uses their job description in a deliberately uncooperative way, or who seemingly delights in acting in an obstructive or unhelpful manner.
The word comes from a common expression used by such people, e.g.
"Could I park here just for a few minutes? I need to collect an urgent prescription of heart medicine for my mother?"
"No, sorry, it's more than my job's worth to let you do that."
In other words the jobsworth is using the excuse that they will get sacked from their job if they bend the rules even slightly.
A low-status employee inclined to abuse power within the public domain is sometimes referred to as a petty bureaucrat.
"However, since these petty bureaucrats’ power is almost absolute, they also control the channels for addressing grievances."
"Any system of universal ID, once established, is the slippery slope, it is a short step to then requiring people to have and carry ID cards which petty bureaucrats and police can demand at will."
Examples from Globse.
Abuse from a petty bureaucrat may express itself as simple disregard or lack of consideration, passive aggression, the imposition of unreasonable obstacles, or outright demeaning behaviour towards a client or customer.
Patrick M (see comments below) suggests petty tyrant as another common idiom for a person who abuses his or her power. This American Life devotes a 45 minute broadcast to the story of a particular petty tyrant, a janitor who rose through the ranks to become head of maintenance,
"when he starts messing with his employees. Teasing them at meetings. Punishing them with crummy work assignments. Or worse things like slashing their tires in the middle of night." Patrick M notes that, although the janitor may have started out as a petty tyrant, he turned into a full-blown psychopath.
The petty bureaucrat and the petty tyrant are but two roles taken by people in positions of relative power without status. Abuse of power by people in low status roles may take on grotesque forms such as the demeaning behaviour of soldiers in the Abu Ghraib prison in Iraq. See The destructive nature of power without status. Journal of Experimental Social Psychology (2011) by Nathanael J. Fast, Nir Halevy and Adam D. Galinsky.
The study On the Ethics of Intervention in Human Psychological Research: With Special Reference to the Stanford Prison Experiment (P.D.F.), undertaken by Phillip G. Zimbardo suggests that ordinary people placed in low status, high power positions--temporary prison guards--will carry out abusive behaviour towards innocent peers.
The abuse of power was even more powerfully demonstrated in the classic obedience studies carried out by Stanley Milgram. (Milgram, Stanley. "Behavioral study of obedience". The Journal of Abnormal and Social Psychology 67.4 (1963): 371). But who is the greater abuser of power? The experimenter who demands that electric shocks be applied to a victim, or the experimental subject who is placed in the role of a "teacher" who must punish the "student" each time the student makes a mistake on a trivial word-pair memorisation task?
Drunk with power. It's pretty self explanatory and applies universally to the obnoxious and abusive wielding of power, no matter how big or small.
In a work environment context, slave driver is appropriate because it's describing one with authority over another in reference to all the scummy negatives that come along with the implication of being involved in the slave trade.
In a general context, "surprised he/she can get their head through the door" may also be appropriate, referring to the inflated ego that these types get when anything complimentary lands in their lap. However, this isn't specific to obtaining power or authority, but it can still apply nicely.
"You see the way Jim has acted since his promotion? I'm surprised he can get his head through the door."
Tin-pot Napoleon is also used. Earliest date I'm finding is a book title from 1932: Amazon:
The Career of a Tinpot Napoleon: A Political Biography of Huey P. Long --- by John Kingston Fineran
(Huey Pierce Long, Jr., Governor and Senator from Louisiana)
The phrase may go back further, but Google ngram is not being helpful this morning, and tin-pot vs tinpot obfuscates matters.
There is an idiom Give somebody an inch and they'll take a mile (See theFreeDictionary) and it does get used to refer someone who has been given a little of something and they make the worst/best/most of it.
I think this expression comes close, bossy boots. The term can be applied to someone who thinks they can order people about because they have a modicum of responsibility. Very often used with young women who are used to having things their own way, or with small girls who boss their siblings.
Macmillan Dictionary tells us
someone who is always telling other people what to do, in a way that annoys them
A toxic leader is a person who has responsibility over a group of people or an organization, and who abuses the leader–follower relationship by leaving the group or organization in a worse-off condition than when s/he first found them. The phrase was coined by Marcia Whicker in 1996 and is linked with a number of dysfunctional leadership styles.
Other names include the little Hitler, manager from hell, The Toxic Boss and boss from hell. Their leadership style is both self-destructive and ultimately corporately harmful as they subvert and destroy organisational structures.
A nice adjective for this is power happy. Example:
Cons [of working in particular company]: District Manager is power happy. No matter how much your store prepares nothing will ever be right for him. Stores call each other to warn that he's headed to their store for what's called a "Store Walk". etc.
I might call such a person a martinet.
a would-be dictator or tyrant.
- would be - wanting or trying to be (Cambridge Online)
- "a would-be actress who dresses up as Marilyn Monroe"
- "He's a would-be politian. Just pay attention to how he talks"
- "Opera singers and would-bes should practice at least four hours a day."