What I found was that a perl script could be written in just a few hours that could completely automate this process, including spoofing new IP addresses on each "vote" to make detection difficult. Spoofing IP addresses is easy if you don't need to receive back bytes from the url you have hit. In the case of these online polls, all you do is hit the form to cast your vote, and it really doesn't matter if the confirmation page packets do not get back to your program.
Please note that if they are spoofing IP addresses to carry out this attack, then this is potentially a FELONY. It's quite possible that if caught somebody could do jail time for this. (Although, it's unlikely the networks who run this site would care enough to prosecute so maybe not.)
This could be solved by having the online form prompt the user to type in a string of distorted digits chosen randomly. Only humans can perform this task. This method is used by many registration systems such as free online mail systems to ensure robotic programs are not abusing the system. But none of the online polls I've seen are doing this.
My bank does this, also.