Democracy is able to survive because it allows the people to be free. In these societies people have the right to vote an influence government. Many of the most successful nations are democracies. Many nations without freedom have fallen do to the lack of patriotism and hope.
The president approves or disproves bills that are forwarded to him/her by the legislative branch. This was because they could not make a proper decision or it was a 50/50 split between Ye or Nay.