One former Mexico City mayor with a suspicious fortune coined a phrase about it: "Un politico pobre es un pobre politico," said the late Carlos Hank, meaning, "a politician who's poor is a poor politician."
For decades, many Mexicans were resigned to that kind of attitude. But finally, public anger is forcing change.
Under pressure, Mexico's congress has passed a law to create a so-called anti-corruption system. Activists have built a web platform to pressure political candidates to show their wealth. And journalists have exposed corrupt acts, resulting in resignations.
Mexico still has an uphill struggle. It's tried to tackle corruption before. But some here are hopeful that this new momentum will lead to long-term improvements.