JEFFREY BROWN: And we return to the Egypt story with a look at the makeup of the opposition and what can be expected after President Mubarak's announcement.
The protesters who filled the streets of Cairo today were united in one thing.
HAMDEEN SABAHI, Al-Karama opposition party leader (through translator): We want Mubarak to leave, and it is his choice how he will leave.
JEFFREY BROWN: But beyond that shared goal, opposition to the regime has come from numerous groups, with sometimes conflicting agendas.
The protests were originally driven by the April 6 group made up largely of young people frustrated with economic hardships and repression, who spread the world on the social-media websites Facebook and Twitter. By the weekend they were joined by the Muslim Brotherhood.
MAN: I want Sharia law, because Sharia and Islam is our religion.
JEFFREY BROWN: The Islamic fundamentalist group is formally outlawed in Egypt. Egypt's then Prime Minister Ahmed Nazif defended that policy to the NewsHour's Margaret Warner in 2005.
AHMED NAZIF, former Egyptian prime minister: Well, the reason is that, when we look at the history of the Muslim Brotherhood itself, they're not pro-democracy. They say today that they are, but their history doesn't say that. So, it keeps us -- we -- we are a little skeptical.
JEFFREY BROWN: A key question has been how much opposition groups will coalesce around Mohamed ElBaradei, former head of the U.N. nuclear agency and Nobel Peace Prize winner. He returned to Cairo after the protests erupted.
MOHAMED ELBARADEI, Nobel Peace Prize laureate (through translator): I hope that President Mubarak agrees to leave the country after 30 years in power. I don't imagine him seeing more bloodshed.
JEFFREY BROWN: The U.S. ambassador in Cairo, Margaret Scobey, spoke by phone with ElBaradei today, but there was no word what they discussed.
Egypt also has several opposition political parties and figures, including Ayman Nour, who ran in Egypt's first multicandidate presidential election in 2005. He was later jailed for three years on forgery charges.
AYMAN NOUR, member of Egypt Parliament (through translator): I challenge President Mubarak, and I will win even from behind these bars.
JEFFREY BROWN: In Cairo today, a second round of opposition talks aimed at developing a coordinated strategy apparently broke down, after youth groups boycotted over charges that traditional parties had agreed to a dialogue with the new government.