I am not going to be popular with this opinion, but here goes:
I like the way the system in the US was originally set up (with a few exceptions). Obviously, race and gender should not preclude anyone from voting. Originally, as a Democratic-Republic, only the land owners could vote. The founding fathers warned (repeatedly) against forming a democracy. To them a democracy was a dangerous concept as people will tend to vote money into their own pockets and causes over the good of the nation.
In the original model, the president was not popularly elected at all. Andrew Jackson was the first president that was elected via a national election. Prior to that, each state had its own method for picking the electoral college. The president was more like a chairman than what he is today. Once presidents became elected nationally, we began to get less than the cream of the crop of electable candidates. Now they have to appease the masses rather than be a strong, decisive leader.
It was not until the early 1900's that Senators were popularly elected. Now it is nearly impossible to get a Senator unseated. They do not have enough accountability.
If it were my choice, only those who actually pay taxes would vote. That means you are a productive member of society with some stake in how your taxes are spent. Oh yeah, I think there should be a test. If a person knows who won American Idol, but cannot name their state representatives, they should not be allowed to vote.
I am standing by for my flaming. Peace out.