Justice League Action Figures

Usually the members of the JL votes in the leader. And the majority of the time, Supes got voted in by the supporting cast.
And ironically enough, Stan Lee would NOT have any comment on whether Supes would lead or perhaps Batman, or the Martian Manhunter, though those two would be excellent leaders too. Stan Lee is the president of Marvel, not DC!
I think the JLA operates much like the X-men do – several field leaders in case one of them is knocked out or otherwise occupied. Hence why Batman seems to have quite the voice among the lot, as do J’onn.

In Ye Olden Days, there was a rotating chairmanship — although Hawkman was virtually permanent chairman of the JSA — and there were periodic votes by the membership. I think the JLA defers to Superman because of his role as the first and most powerful superhero. If Kal has one power that none of the others posseses — or, more properly, if he’s written correctly, he posseses it — it’s the power to know what the right thing to do is. That alone gives him the moral authority the others look up to.
In the JLU cartoon, Superman seems to be the leader, but J’onn does the coordinating of resources and Batman is the strategist.

Superman is supposed to be the leader because he is the most popular and strongest superhero there is(in DC comics at least).
Batman is also very important, as the answerer above me says it well.

every one is too scared to fight him for leader ship ^_^. so he just said im leader, and everyone agreed.

He doesnt need no votes.

Actually the truth is neither Superman nor Batman are deemed the leaders. Those of you who have been keeping up know that since the “All knowing Eye” where the Omacs were being created. Batman was actuall a creator of a program in case Superman became a threat. Which he had become and nearly killed Batman, due to mind control of I don’t remember his name like chesspiece or something…any ways..Jo’on is the current leader. (Martian manhubter.)

The vast majority of the people that read comic books. I would say that everyone from the guy working in the mail room all teh way up to the Reverend Stan Lee himself would agree if they were asked in public and didn’t give a cop-out answer.