I'm not the best human being in the world by a long shot. But I don't steal egregiously (I do admit to pilfering bandwidth and violating some laws designed to protect artistic and creative content). I am basically honest. I give to charity. And I don't need God to be this way.

Why am I forced to pay more than my fair share of taxes simply because a church is exempt? Why must I subsidize someone else's beliefs financially?

I believe one of the main reasons religious leaders appear to have the edge, looking back through history, is the nature of their work. Their speeches tend to be very inspirational, uplifting, etc. They spend more time in front of people than your typical community leader or politician. They are usually more empathetic and are much better at the human level.

The thing is, any respected community leader has the ability to mobilize en masse and lead the people on a crusade to do whatever. The two key components are not religious or non-religious affiliation, but the community itself and the ability of that leader to connect on the human level.

If a community is highly religious, then the people probably would be difficult to mobilize without direct involvement by the religious leaders. However, in a non-religious community, a religious leader would have a much more difficult time gaining traction. Unless, that leader is highly respected in the community.

Typically you would expect your other non-religious leaders to be your politicians. However, that kind of change seems to be rather rare in that most significant cultural and societal changes involve changing the system. Those changes are usually not good for the entrenched civic leaders. Therefore, even if they have the ability to mobilize and inspire, they typically lack the motivation to do so.

Regarding slavery in the US, while its end may have been lobbied for by various parties, etc., it was Lincoln, a politician (and rumored atheist by historians, though his religious views have never been verified), that said 'Enough' to slavery. Without him taking that stand, who knows when it would have ended? Another 10, 20, even 50 more years?

I would say, that religious figures are not required to mobilize en masse. Most religious figures are not necessarily natural born leaders. That is why they spend a lifetime learning their religion and how to preach it. Almost any person, given a lifetime of practice, can become a leader. Religions just seem to have more practice at it.