The inhabitants of the united states have had influence on their countries politics for so long that they think it their right to be able to vote. However, most of all the humans ever born lived under a government that did not give official rights to vote for leaders, and still lived completely natural lives. Although one can argue that in an ideal world everyone would be able to vote, we do not live in an ideal world, and so it cannot be a natural right. We are clearly very privileged people to reserve that power.
All citizens should have the right to vote. Voting guarantees that no single person has too much power. If power is shared, and people get to chose their representatives, the government will be more fair and transparent. If a single person is too powerful, they will almost always end up corrupt.
I believe that the voting is both a right that applies equally to citizens over the age of 18 and not a criminal. I think while it should not be a privilege we are privileged to be able to vote for those we believe will represent us fairly on topics we feel are important.