What really happened in the Gingrich ethics case?

The Romney campaign has been hitting Newt Gingrich hard over the 1990s ethics case that resulted in the former Speaker being reprimanded and paying a $300,000 penalty. Before the Iowa caucuses, Romney and his supporting super PAC did serious damage to Gingrich with an ad attacking Gingrich’s ethics past. Since then, Romney has made other ads and web videos focusing on the ethics matter, and at the Republican debate in Tampa Monday night, Romney said Gingrich “had to resign in disgrace.”