The right to run for president is severely limited. A candidate must belong to a legal party that won at least 3 percent of parliamentary seats in the previous election – a hurdle that few political parties other than Mubarak’s National Democratic Party (NDP) can clear. The Muslim Brotherhood – Egypt's most organized opposition group – is banned and therefore its candidates have to run in elections as independents, making them ineligible for the presidency.
There are some ways around that requirement. According to Reuters, if an independent candidate can get endorsement from 250 elected officials, he or she can stand in a presidential election. But that’s a hard standard to meet in Egypt.