Should mentally ill be able to vote?

http://www.cnn.com/2008/POLITICS/10/31/mentally.ill.voting.ap/index.html?iref=newssearch

For some reason I thought this was posted around the election but I only saved it as a draft. Anyway, this article was very interesting and more or less just talked about state advocates trying to help people who had a mental illness register and be able to vote. However, on absentee ballots people who help you are supposed to sign their names but are not allowed to influence your vote. One of the big arguments against allowing this is that people helping the disabled vote could be influence the vote or putting who they'd like to win. Only eleven states do not have laws limiting voting rights based on competence. Experts said that since mentally ill rely on the government so they should be able to vote. What do you think? I think that since America is suppose to guarantee equal rights, all citizens should be able to vote. Even if they are not able to closely follow an election, they are still entitled to vote. There are plenty of people who barely follow the election and go out and vote for whomever they like. No one should be able to decide who is "able" to vote. If a person is willing, then they should be allowed to.