Egyptians argue political issues in front of an anti-government mural a day before presidential elections on May 22, in Cairo, Egypt. Egyptians go to the polls Wednesday and Thursday to choose a new president, the first of the post-Mubarak era. If no candidate wins a majority vote this week, a second round election will be held between the top two candidates on June 16-17.

A pedestrian walks past an Egyptian army convoy patrolling the streets a day before presidential elections on May 22, in Cairo, Egypt. Egyptians go to the polls Wednesday and Thursday to choose a new president, the first of the post-Mubarak era. If no candidate wins a majority vote this week, a second round election will be held between the top two candidates June 16-17.

An Egyptian worker checks boxes containing ballots a day before the presidential election in Cairo on May 22. The election that starts on Wednesday is the last stage in a messy transition to democracy, overseen by generals who took control after Hosni Mubarak was driven out and have pledged to hand power to a new president by July 1.

An Egyptian army officer gestures as he and colleague ride in a vehicle with a megaphone to call Egyptians to vote, in central Cairo's Tahrir Square on May 22, one day before the country's landmark presidential elections.

AFP PHOTO/MARCO LONGARIMARCO LONGARI/AFP/GettyImages

President Barack Obama greets a graduate before making the commencement address at Barnard College on May 14 in New York.

Graduates listen to Barack Obama give the commencement address at Barnard College in New York City.

Petitioners protesting about medical and land grab issues are detained by police outside the Chaoyang Hospital where blind Chinese activist Chen Guangcheng is being held, in Beijing on May 8.

A petitioner, allegedly persecuted by local officials after reporting a corruption case to the central government, shows a scar, trying to attract public attention for his case, while he is grabbed by a policeman outside the hospital where blind activist Chen Guangcheng is staying for treatment in Beijing, China, Tuesday, May 8.

A petitioner amongst a group protesting about medical and land grab issues is detained by police outside the Chaoyang Hospital where blind Chinese activist Chen Guangcheng is being held, in Beijing on May 8. Blind activist Chen Guangcheng said May 8 he has met government officials about getting a passport, raising hopes he may soon be able to leave China, but US embassy staff still cannot visit him in hospital.

Security guards talk outside the Chaoyang Hospital where blind Chinese activist Chen Guangcheng is being held, in Beijing on May 8. Blind activist Chen Guangcheng said May 8 he has met government officials about getting a passport, raising hopes he may soon be able to leave China, but US embassy staff still cannot visit him in hospital.

President Barack Obama presents a birthday cake to Bloomberg White House reporter Julianna Goldman as she blows out the candle aboard Air Force One during the flight to Washington from Afghanistan May 2, 2012.

Egyptian anti-military protesters evacuate a demonstrator after he was wounded by rubber bullets during clashes in the Abbassiya district of Cairo on May 2. They wereattacked at an anti-military protest near the defence ministry in Cairo and several people were killed, officials said, in the politically tense run-up to the first post-uprising presidential election.

Protesters clash with Egyptian military outside the Defense Ministry in Cairo, Egypt, Wednesday, May 2. Suspected supporters of Egypt's military rulers attacked predominantly Islamist anti-government protesters outside the Defense Ministry in Cairo Wednesday, setting off clashes that left more than ten people dead as political tensions rise three weeks before crucial presidential elections.

Islamist protesters and their supporters run during clashes with armed "thugs" after an attack on protesters late Tuesday night, in Cairo May 2. Eleven people were confirmed dead after thugs attacked the protesters demanding an end to military rule after their candidate was barred from this month's presidential election.

Islamist protesters and their supporters clash with armed "thugs", after an attack on protesters late Tuesday night, in Cairo May 2. Eleven people were confirmed dead after thugs attacked the protesters demanding an end to military rule after their candidate was barred from this month's presidential election.

Egyptian protesters beat a man as he tries to escape on the back of a motorcycle after he was accused of attacking demonstrators in the Abbassiya district in Cairo on May 2. At least 12 people were killed when attackers stormed an anti-military protest near the defence ministry in Cairo, medics and a security official said. The fate of the man is unknown.

An 'Occupy London'' protester hands out flowers to commuters in a central London train station to mark May Day, May 1.

People march on a sidewalk during a May Day protest in New York on May 1. People around the world are gathering for May Day protests against austerity measures and calling for higher wages. In the United States, the Occupy Wall Street movement is trying to use May Day to rejuvenate.

Workers clean the vandalized windows of a Bank of America branch in Washington, Tuesday, May 1. In the US, May Day demonstrations, strikes and acts of civil disobedience were planned, including what could be the country's most high-profile Occupy rallies since the anti-Wall Street encampments came down in the fall.

A protester affiliated with the Occupy Wall Street movement is stopped by the police as he stands in the middle of Sixth Avenue during a protest march to the Bank of America headquarters in New York City May 1. Occupy Wall Street joins labor groups for a day of protests on Tuesday to mark International Workers Day and to try to breathe fresh life into the movement that sparked a wave of nationwide protests against economic injustice eight months ago.

California Highway Patrol officers take positions at the Golden Gate Bridge in anticipation of May Day demonstrations in San Francisco, California May 1. Authorities anticipated demonstrators would shut down the bridge, but agreement was reached to prevent that action.

People march past a bank during a May Day protest in New York. People around the world are gathering for May Day protests against austerity measures and calling for higher wages. In the United States, the Occupy Wall Street movement is trying to use May Day to rejuvenate.

Occupy Wall Street demonstrators dance as hundreds of protesters gather during a May Day labor rally in Bryant Park on May 1, in New York City. Demonstrators have called for nation-wide May Day strikes to protest economic inequality and political corruption.

Election worker Khalid Battle reads a book as he waits for voters to cast their ballots in Pennsylvania primary election at Memorial Gospel Crusades Church, Tuesday, April 24, in Philadelphia.

Brendan Reilly, right, completes an election affidavit prior to casting his ballot at a polling station in the lobby of his apartment building on Wall Street in New York, Tuesday, April 24. Voters in New York, Connecticut, Delaware, Rhode Island and Pennsylvania are voting in the presidential primaries Tuesday. Reilly, who voted for Ron Paul, is hoping for a brokered Republican convention to block Mitt Romney's nomination.