Amending the United States constitution, grating it's citizens the ability to repeal or veto a law by way of referendum, would protect be a safeguard from special interests of politicians. This system already exists in several other countries (such as Switzerland, Denmark, Italy, Russia, and Venezuela) and in 23 states of the USA.
Once citizens get a significant number of signatures, the petition would be submitted to the government, which would create a national level referendum, in which the people would vote on whether or not the recently passed legislature should be repealed. If three fifths of the voters select to veto or repeal a recently passed law, the new law shall be stopped and would not take effect. If less than three fifths vote against the law, it shall take into effect.