“It’s never entirely clear with the Brothers,” says Josh Stacher, a political science professor at Kent State University who spent years in Egypt studying the organization. “It’s a big group, with lots of different points of view. You can find the guy always screaming about Israel and then you got the other guys who don’t care about Israel because they’re too busy worrying about raising literacy rates.”…

The outlawed Islamist opposition group is plagued by rifts between young and old, reformist and hard-liner. There are big city deal-making politicians, and conservative rural preachers who eschew politics in favor of proselytizing Islam…

In recent years, meanwhile, the group’s pragmatic wing has forged a historic alliance with secular opposition activists. Their role in the unseating of Mr. Mubarak appears to have given them a boost in a struggle for influence with the Brotherhood’s fiery old guard.

“The Muslim Brotherhood as a whole doesn’t deserve credit for this revolution, but certain factions within the movement absolutely do, generally those that have more modern views,” says Essam Sultan, a former member of the group who left in the 1990s to form the moderate Islamist Wasat, or Centrist, Party. “That wing should get a massive bounce out of this.”