Kentucky voters who want to switch political parties have until Friday, December 31 to do so if they want to cast ballots in the May primary.Les Fugate with the Secretary of State's office says it's as simple as filling out a voter registration card."They can either take it directly into their county clerk's office, or this is actually one of the few times with voter registration that the postmark will be acceptable. So as long as you get it postmarked by the 31st, the county clerks will accept that," he said. Fugate says switch cannot be made online because a signature is required, but the registration card can be printed from a website.