A piece like the one Marc Lynch wrote at Foreign Policy comes out periodically, questioning the relationship between the United States and Saudi Arabia. It's a great relationship to question and I've done the same on occasion as well.
Our relationship with Saudi Arabia is complicated for more reasons than oil. Saudi Arabia, either with our explicit permission or acquiescence spread money and resources around to groups that can and do needle Iranian interests in the region. I think it's fair to say the aid Saudi Arabia has given to Syrian rebels in dollars and weapons have helped sustain the fight there, but it's not a country remotely interested in becoming a liberal democracy. We need to square that circle, lest we continue to be enablers of Saudi Arabia in the future.