On page 13 of "Industrial Strength Power Teaching", it tells you to have the kids *nominate* who they think would be positive leaders by writing it down and submitting it to you, but that you are the 'leader of all leaders', and you will pick the kids that you think will do the best job.
It's not some total farce, but you do want to remain in control, so you always tell the kids that you have the final say. This means, don't count the votes in front of the class and tally them on the board... but take them home, or look at them after the kids go home, and analyze the results -- will these results bring about the change you are looking for? Will the class follow these leaders?
Then notice on step seven on page 13, it says, "Choose the kids that have the best chance of being positive leaders. If a good student was not nominated, add him/her to your list." 'Good student' meaning, good candidate for leadership. Plenty of 'good students' are not leaders... so keep leadership qualities in mind.
You don't have to go back and tell your class that you made changes to their nomination list, but you did tell them up front that you...always... have the final say.