The role of religious extremism in America is that it is poisoning the well of American politics, making our elected bodies weighed down in hot-button measures. Examples:

Va. Republicans vow to protect religious rights after gay marriage ruling

SSM is red meat for politicians to throw in front of the religious right voters:

Kansas governor signs religious freedom executive order

I see the end result of all of this as stultifying the political process to tackle real problems, where pressing issues or larger systemic issues (e.g., banking regulation, or climate change) are not dealt with because hot-buttons are the name of the game.