During the 1870s, Thomas Nast famously campaigned against corruption in New York politics, mercilessly skewering "Boss" Tweed's Tammany Hall machine in Harper's Weekly. "We gotta stop them damned pictures," Tweed privately complained. "I don't care so much what the papers write about me -- my constituents can't read. But they can see pictures."
Sure enough, one of these "damned pictures" led to Tweed's undoing. Having been imprisoned, he escaped in 1875 and left the country. While living incognito in Vigo, Spain, he was recognized (from Nast's caricatures), arrested, and promptly returned to America.
[Our image of Santa Claus stems largely from Nast's depiction of St. Nicholas.]