By Tom Perry
CAIRO (Reuters) - One is a former military man proud of his links to the Hosni Mubarak era and the other a Muslim Brotherhood leader offering a dramatic break with the past. Both are polarizing Egyptians in their bid to become president.
Ahmed Shafiq, Mubarak's last prime minister, and Mohamed Mursi, the Brotherhood's presidential hopeful, have joined the front runners in the race, their chances buoyed by campaigns that only gathered pace in recent weeks.
The two men starkly capture the historic moment facing Egypt and the Middle East when voters head to the polls on May 23-24 for an election whose outcome is proving hard to predict. They are broadly seen as the most divisive of five front runners in the race to replace Mubarak.
A Shafiq win would keep the presidency in the hands of a man with a military past, extending the pattern established in 1952 when army officers overthrew the monarch - an outcome reformists fear will crush their hopes for change.
A Mursi win would hand the leadership of the Arab country to the Muslim Brotherhood - consolidating its influence in a historic shift with regional consequences analysts say could set off new power struggles within the state.
It faces competition in the shape of veteran statesman Amr Moussa and independent Islamist Abdel Moneim Abol Fotouh, who have both sought to distance themselves from their past lives in government and the Muslim Brotherhood. Hamdeen Sabahy, a leftist, is also seen among the front runners in a field of 12.
But while Moussa and Abol Fotouh try to shake off their past affiliations, Shafiq and Mursi are banking on those very same links to rally voters at opposite ends of Egypt's fast-evolving political spectrum, who either see an old guard figure as a vote for stability or an Islamist as a vote for much-needed change.
"It will complicate and make it more conflictual if Mursi or Shafiq wins," said Joshua Stacher, a political scientist and Egypt expert based at Kent State University in the United States.
"The chances for more street activity will be incredibly high," he said. "There is a real possibility that if the Muslim Brotherhood were to win, that the military could shut down the state bureaucracy on them."
Shafiq, 70, has openly expressed his admiration for Mubarak, making no apologies for a remark he made in a 2010 interview in which he described the former president as his role model, after his father.
"See what I said? And I will keep telling you this until the last day in my life, and for a reason: he had great courage," Shafiq said, when asked about the remark in an interview with the al-Hayat channel, posted on YouTube in April.
The 61-year-old Mursi, meanwhile, is a long-serving Brotherhood man, who is depending more on the group's formidable organizational network than his own popularity to win.
The bespectacled engineer, described as "a graduate of the Brotherhood nursery" by the group's leader, was thrust into the race just a month ago by the disqualification of the party's first-choice nomination, Khairat al-Shater.
In an increasingly heated campaign, Mursi, Shafiq and others have been targeted by protesters during the last few weeks. One man threw a shoe at Shafiq during a rally in southern Egypt on Thursday.
Shafiq has come to embody all that Egyptians who took to the streets on January 25, 2011 wanted to change in their country and an attempt by the old regime to reinvent itself.
The Brotherhood, though part of the reform movement, has faced growing anger over its policies during the last year.
Its critics accuse it of seeking to dominate - charges it fiercely denies but which have added to long-held suspicions surrounding a movement demonized by the state for decades and still shrouded in mystery to many.
Hassan Nafaa, a professor of political science at Cairo University, said victory by either would deepen the polarization in Egypt. He has endorsed Abol Fotouh for the presidency.
A Shafiq presidency, Nafaa said, would be a "reproduction of the old system through some new names".
Were the Brotherhood to win, he saw the chance of another military takeover. "I am afraid that this kind of polarization will reproduce a coup," he said.
(Additional reporting by Omar Fahmy; Writing by Tom Perry; Editing by Sophie Hares)