It's a lobbying group with lots of money that tries to influence Congress.
It does not control Congress, unless Congress allows itself to be controlled.
The people elect Congress, and have the option of not reelecting Congressmen. They are not cut out of the loop, though many if not most are poorly informed.
They utilize the biased media and their large sums of money to distort people's view of the world through half-truths, and outright lies to push an agenda.
They however still need the support of the American people in order to push their agenda forward. While they often attempt to achieve that support through rather transparant deception, they receive an appalling amount of support from the American people.
None of this however is justification for calling Bush a domestic enemy and suggesting he should be impeached over the comments of this group.