This is easy, but would require a complete upheaval of our current campaigning methodologies. With the internet, there is no excuse for not implementing an entirely new methodology.
No more voting upon promises made by wanna be politicians.
Simply form a government sponsored web poll which tallies the most important issues and positions that the people of our nation believe in. Provide an area to debate the issues amongst the people sans any lobbyist involvement. Another area would be designated for lobyyists and advocacy groups to put forth their positions. People would only be allowed to register their polled opinion after completing a review of all sides of any argument. Verification would be handled by a simple questionnaire confirming that the person has educated themselves completely on whatever it is that they wish to cast their poll.
Politicians would be hired to put forth the will of the people. They would be required to not take a stand on anything themselves. Their entire job revolves around enforcing the poll.
If a particular group doesn’t like the results, then they have an open platform to sway public opinion towards their position. This is a return to public forum debate akin to ancient Greek society where any man could stand in front of his peers and offer well reasoned logical arguments for or against any position. The council is swayed by logic, and not any one mans private agenda.
We live in The Age of the Petabyte where truth is beginning to speak for itself, rather than being interpreted through the jaded eyes of humans. We would do well to accept that truth for what it is, rather than what some private corporation or political posturing would like it to be.