One day, a long long time ago...
Dave was a Democrat. He was raised a Democrat by his Democrat parents, and believed that Democrats would be the saviors of America. He even had cardboard cutouts of all the Democratic candidates to ever run for president situated around his room, especially around his bed and facing towards his windows (it made him feel safe at night). He was as Democrat as Democrat could be, so that's why it surprised everyone that, when he got old enough to vote, he registered as a Republican.
"Don't worry" he told his concerned parents "I only registered as a Republican so that I could vote for their stupidest, jackassiest candidate. That way, there's no way the Democrat candidate will lose!"
Dave also had a best friend, Rory. Rory was much like Dave, except for the fact that he was a year younger, had a pet pygmy elephant, and loved to throw darts at his dart board in his free time, which had a picture of Mark Dayton on it. Yes, Rory was a die hard Republican.
One night, Rory was with Dave's mom. He asked her why Dave had chosen to be a Republican (not that he minded the decision). Dave's mom explained.
"You see, he's going to vote for the most idiotic, jackassiest candidate in the Republican party. That way, the Democrats will never lose"
Rory nodded, liking the idea. So next year, when he registered for voting, he registered as a Democrat.
Rory's cousin heard about it, and did the same. Dave's girlfriend heard about it, and both her and the boy she was cheating on Dave with did the same. Eventually, enough people transferred parties that BOTH jackasses were the ones that got the most votes
...now do you see the problem?