[Benjo]

I'm not sure if you are disputing the claim that lobbying is increasing. Here's some data: http://www.opensecrets.org/lobby/index.php Looks to be trending upwards fairly quickly with the exception of 2010. I would assume that represents information not publicly available due to the effects of the Citizens United decision.

Is lobbying a result of income inequity? I think it has more to do with the increasing power and competition between corporations than individual wealth. The more competitors one has, the more likely that one has to match their lobbying efforts just to keep the playing field even.

Beyond that, the effectiveness of lobbying enables the rich to exert more influence over the election process. It may be because our election system is not insulated against this influence that the income distribution seems so unfair. This would imply that we should reduce that influence or reduce the inequity of wealth. Which one is more fair, if they can even be done separately, is not clear to me.