Right now, who becomes the commander is most often decided by who is the closest person to the chair who fancies themselves a comm at the beginning of the game, which strikes me as a rather random way of determining who gets to play the most important role on the marine team. Sure, people can vote out a commander, but that usually only happens when the commander is deemed to be "bad" by a very significant portion of the marine team - the result is that only the very worst commanders are ejected, while many commanders that can barely manage to stay above your average player's idea of what is acceptable remain in the chair (My, doesn't this sound like politics?)
So, here is my suggestion: At the beginning of each round, set aside some time for a pre-game phase (Perhaps 45-90 seconds?), where each team can discuss strategy, assign roles, and - you guessed it - vote for a commander. The specifics can be tweaked, but I'm thinking that each player gets two votes for their choice of commander (although the two votes cannot go to the same player). The commander is then selected by probability (Ex. 8 votes out of 24 total votes gives you a 1/3 chance of being selected). Any player can remove themselves from the ballot (Nobody wants an unwilling commander), and during the game itself, the traditional commander ejection system would remain as a means to remove an AFK/miscreant/whatever commander.
Don't bother posting, because it seems to me, you don't even know how the game works.
THIS SIGNATURE IS IN VIOLATION OF COMMUNITY RULES