JUDY WOODRUFF: Now, The Muslim Brotherhood scrambles the race for the presidency of Egypt.
Margaret Warner has our story.
MARGARET WARNER: When protests swelled in Cairo's Tahrir Square a year ago, the Muslim Brotherhood initially kept a low profile. But before long, Egypt's oldest Islamic movement, banned from politics under President Hosni Mubarak, joined the young revolutionaries.
And since then, with a military council running Egypt, the Brotherhood has emerged as a powerful force. It won nearly half the seats in parliament's lower house. And another, more fundamentalist Islamist group, the Salafis, won more than 20 percent.
At the outset, the Brotherhood pledged not to run a candidate for president, saying it wasn't seeking a monopoly on power. But last Saturday, it did just that, nominating Deputy Chairman Khairat al-Shater to run.
The U.S. reacted cautiously, with Secretary of State Hillary Clinton saying Sunday, "We hope that the Egyptian people get what they protested for in Tahrir Square. And that's complete, open, pluralistic democracy that respects the rights of every Egyptian."
The leading moderate in the presidential race, Amr Moussa, voiced hope about Egypt's political prospects two weeks ago.
AMR MOUSSA, Egyptian presidential candidate: I believe once the president is elected and the constitution is on the way to being drafted and a new government, and this will create a balanced approach towards the future. I am optimistic. In fact, I'm not pessimistic at all.
MARGARET WARNER: A poll of Egyptian voters released yesterday showed Moussa, former head of the Arab League, remained the frontrunner. An ultra-conservative Islamist, Hazem Salah Abu Ismail, was still running second.
In the meantime, late last week, liberals and Coptic Christians protested the makeup of the panel writing the new constitution. They charged, Islamists are trying to hijack the process.
WOMAN (through translator): We will only accept Egypt civilian rule. Egypt is not Muslim Brotherhood or Salafi.
MARGARET WARNER: But the possibility of total Islamist control is now at stake in the first round of presidential balloting in late May and the runoff, if needed, in June.