Some people want to make the world a better place. They run for office and stay up late trying to help their constituents. This is not their trope.
This politician sees the world through Jade-Colored Glasses. He thinks it's a World Half Empty, with Black and Gray Morality. He's gotten family members appointed to positions and his friends get the government contracts he doesn't keep for himself. A constituent who comes to him for help had better be ready to hand over a juicy "campaign donation".
Some corrupt politicians just abuse and twist the system for their own ends. Nepotism may or may not be illegal, and steering contracts to your friends may just be the result of a small pool of available contractors, and of course a member of the committee for Big Oil is going to be acquainted with Big Oil. On the other hand, some are fully criminal and allied with The Mafia or some other criminal organization. They use their insider status to steer police investigations away from their crimes and exploit loopholes, engineer loopholes, or simply get rid of the law on their behalf.
A Corrupt Politician can be as minor as the mayor of a small town, a Corrupt Hick who runs everything for his own benefit. Or he could be President Evil, a full blown super villain in charge of an entire nation. Taken to the extreme, he's an Evil Overlord.
When you walk into a Chez Restaurant, you can expect to find the Corrupt Politician eating dinner with the Corrupt Hick, the Corrupt Corporate Executive, the Police Commissioner and The Don. He's probably on good terms with some evil aristocrats, princes, and queens, as well. Unlike the rest of them, the Corrupt Politician had to go through an election. Or at least the appearance of an election. The Corrupt Politician will assure them all that the Corrupt Bureaucrat, who he appointed, will do what they want.
- Every single politician Batman meets in Gotham with the exception of District Attorney Harvey Dent and Police Commissioner Gordon.
- In the Crapsack World of Basin City, being honest is contraindicated. Any politician who commits an act of honesty is committing an act of suicide.
- Superman's Lex Luthor dishonest? Nonsense! He won a fair election that wasn't rigged in any way.
- The same goes for many members of his Cabinet, including his Sec. of Defense Sam Lane and Amanda Waller, who was appointed Head of his United States Secretary of Metahuman Affairs. (Both were villains in their own right for some time.) Others, like Pete Ross (his Vice President) and Jefferson Pierce (Sec. of Education) were clean.
- Wanted: In a world run by super villains, some of the politicians have to be on the take.
- Watchmen gives us President Nixon on his fourth term, and reporters dead. We can trust the Comedian when he tells us that's a coincidence.
- Asterix in Switzerland has the Roman governor of Condatum who took ridiculously large amounts of tax money in his province for his own purposes while only giving a meager to Rome. The plot itself starts when an inspector from Rome came to his province to investigate this and he was poisoned by said governor, which ended up bringing Asterix and co. into the picture.
- Mr. Smith Goes to Washington has Senator Joseph Harrison Paine (Claude Rains) and Taylor (Edward Arnold), the boss of the machine that controls him.
- The politicians of the new Batman trilogy aren't quite as corrupt. In addition to Harvey Dent, we have an honest judge, an honest commissioner prior to Gordon, and an honest mayor looking to get the mob off the streets. Unfortunately, we also get The Joker.
- Of course, how honest the commissioner was prior to Gordon is iffy, as the mayor implies during his eulogy that the late Loeb had enacted policies that were unpopular to various personnel.
- The Big Lebowski: The Dude's run in with the Malibu chief of police doesn't go well for him. He may not be on the take, but he's willing to beat up a man when a local rich man asks him to.
Chief: Jackie Treehorn draws a lot of water in this town. You don't draw shit, Lebowski.
- The Dukes of Hazzard: See the TV entry.
- Shoot Em Up gives us a senator who sells out to the gun industry after said industry kills his shot at a miracle medical cure. Literally.
- Sin City: See the comic entry.
- In the Star Wars prequel trilogy, Senator Palpatine got elected, maybe even honestly. He's still a Machiavellian, scheming bastard with no ethical values besides prolonging his own stay in power and strengthening his grip on the Republic.
- The film of V for Vendetta turns the Norsefire into corrupt bastards who used a bioterror weapon against their own people in order to fuel their rise to power.
- Watchmen: See the comic entry.
- There's a joke. A corrupt politician is out and about, traveling the world, when he meets an corrupt dictator. They start bragging about their exploits. The politician pulls out a picture and says, "See this bridge? I skimmed more than $5 million during its construction." The dictator pulls out a picture, "See this bridge?" "What bridge?" "Exactly."
- The Hitchhiker's Guide to the Galaxy plays this trope for laughs. The president of the galaxy is expected to be corrupt and is occasionally imprisoned upon election.
- Willard Phule, of Phule's Company, aka Captain Jester, encounters Governor Wingas on his maiden tour after his promotion. The governor eagerly awaits a "campaign contribution" from the newly arrived very wealthy man.
- Senator John Caddrick shows up late in the Time Scout series, is deep in bed with The Syndicate and personally ordered multiple murders. His reputation is fearsome and well-deserved.
- Ender's Game ends with a war for control of Earth as the Chinese, Russians, and the US try to take control of the space fleet. Orson Scott Card's opinion, demonstrated in the parallel series that succeeds it, of the elected Chinese and Russian governments is very poor.
- The governments of the Alliance Union universe are complex, to say the least, with government, economics and the web of alliances all messily tied together, thanks to the vast distances involved in space travel and an FTL drive that isn't magical, and the fact that every space station and space ship is a separate nation. The Viking station is essentially a third world country, with the difficulties that implies, and the Esperance station is a border nation grown fat off of multiple, multiple smuggling operations. The government of Esperance is explicitly corrupt.
- In Stranger in A Strange Land, Jubal Harshaw is glad to learn that Secretary Douglas, head of the Federated Nations, is the sort of politician who, once bought, stays bought.
- Robert A. Heinlein had a dim view of politicians in general and considered an idealist untrustworthy because he'll break any promise if convinced it's for The Greater Good. A dirty politician is trustworthy because he knows he has a reputation to maintain.
- Politicians don't often show up in the Aubrey-Maturin 'verse. Perhaps the most notable exception is Aubrey's father, General Aubrey, MP. Aubrey, in all innocence, tells his father about a stock tip he got. The good General then tells everyone he knows. End result: Aubrey is convicted of the early nineteenth century version of insider trading, spends a day in the stocks, and loses his commission. Nice job, dad.
- Subverted in Small Gods: The ruler of Ephebe is one of the only elected rulers on the Disc and they call him "Tyrant". Generally, he's honest, if somewhat cynical.
- In The Last Continent, we learn that the remote and little-known land of XXXX also has an elected ruler—and a tradition of throwing each new ruler into jail as soon as he's elected, on the assumption that it will save time later.
- Is there a single honest politician in Atlas Shrugged? No. In order to be a politician, you have to want power over others, and that makes you a LEECH.
- There's a parliamentary faction in the Prince Roger 'verse dedicated to overthrowing the Empire of Man which includes Roger's father. YMMV; our freedom fighters are your terrorists, but the series implies that the royal family are dedicated public servants and the faction are in it for personal gain.
- Politics plays a major part in the Honor Harrington series, so of course this trope is in force. Haven's Legislaturalists, Manticore's & Grayson's Opposition parties, and the Solarian League's bureacrats are almost exclusively split between the sleazy and the corrupt.
- The series crowner is probably the Manticoran Progressive Party's leader Lady Elaine Descroix, who is so utterly ruthless and cynical that she makes her own corrupt Prime Minster blanch. We have to go to series reference materials to get a solid idea of what (if any) principles her party actually has, since she vocally disdains politicians who are led by them. She embezzles money and frames her sole semi-principled ally, she doctors diplomatic correspondence to hold on to domestic power and ends up provoking a war, and she turns out to be The Mole for a nation involved in slave trade.
- Insofar as there are politicians in Snow Crash, they're corrupt. Everyone's corrupt. Everything's corrupt.
- In Tad Williams's Otherland, half the members of the Grail Brotherhood are heads of state. The rest merely own heads of state.
- Many politicians in the Star Wars Expanded Universe, many of them Bothans. This is because Bothans have a very ruthless, predatory attitude towards politics, and they see any politician who isn't doing anything in his power and making whatever shady deals he needs to in order to cement his office and get rid of the opposition isn't doing his job right. This is particularly notable in The Thrawn Trilogy, when Bothan leader Borsk Fey'lya does everything he can to ruin Admiral Ackbar and take over his position even when it's detrimental to the New Republic war effort. Thrawn himself notes that he never tried subverting Fey'lya, since he was helping the Empire so well as he was that Thrawn just didn't need to.
- Angel gives us a number of evil, never mind corrupt, politicians, thanks in no small part to the law firm of Wolfram and Heart. Two senators show up on screen, and far more are implied.
- How corrupt is Mayor Wilkinson, of Buffy the Vampire Slayer's Sunnydale? He sold his soul. The only reason Sunnydale exists is because he set it up as a demon/vampire smorgasbord. How does he keep getting elected, decade after decade? See above re: soul.
- Castle gives us a district attorney willing to pervert the justice system to retain the backing of a very wealthy family. A mild example, but he nearly convicted an innocent man of murder to help secure his election.
- There's also Mayor Bob, friend to Castle who features prominently in the episode 'Dial M for Mayor.' There's ample evidence to suggest that he's embezzling funds and was involved in a murder but he attests that he's being set up. Subverted in that he's right and the conspiracy that shot down his run for governor are the same guys involved in Beckett's mother's murder.
- The Dollhouse has a number of powerful connections. Yet another senator cashes in the favor. Hell, they got a doll elected as a senator so they could rig an investigation into them and set it up to fail.
- Near the end of Law and Order's run, we meet Governor Shavloy, who consorts with prostitutes and more.
- Boardwalk Empire is built on this trope as it shows obscene amounts of corruption in all levels of 1920s government going all the way to the White House.
- Fallout: Flip a coin. Then shoot it. If you hit it, the elected official is honest. To be fair, there aren't very many elected officials. A lot of elders and warlords.
- Grand Theft Auto gives us multiple examples. It's Grand Theft Auto.
- Assassin's Creed: Why bribe politicians when you can Mind Rape them? Still, some are Templars, some are Assassins, so this goes both ways.
- Mirrors Edge says that the government has become corrupt, but the ending implies that the world isn't that bad.
- In Command & Conquer's Nod campaign, the faux Risk-Style Map shows, among other information, a percentage of government corruption.
- Mayor Quimby in The Simpsons is a massively over-the-top example. In fact, the mayoral motto is Corruptus in Extremis.
- There is also Congressman Bob Arnold in Mr. Lisa Goes to Washington.
- Mayor Adam West from Family Guy has no problems making deals with big polluters, wasting taxpayer money on solid gold Dig 'Em statues, or killing anyone who questions his methods.
Statler: Corrupt politicians? What other kinds are there?
Waldorf: Unsuccessful ones!
- For saving a man's life. Aubrey asked his father to keep it a secret, just as the stranger did.