Disenfranchise Government Employees
First, I think there's a huge conflict of interest when people who derive their primary source of income from government having a say so in who is elected. Their self interest in voting for those candidates who will be the most likely to increase government spending, resulting in more public dollars flowing into the pockets of those voters is detrimental to the rest of us.
I happen to serve as a member of a local government commission. It's mostly volunteer, but in the interest of full disclosure does come with a small annual stipend. After taxes, I'm left with enough to take my wife out for a couple of nice meals at say, Manny's (including some nice wine) to help make up for the time I spend studying material and attending meetings. But it certainly isn't going to make me rich and it could go away tomorrow and I wouldn't miss it or choose to resign my position.
Every year, we are required to sign an ethics statement that says that we understand and will abide by state law regarding conflicts of interest. Suffice it to say that it's pretty strict. A person that has something coming before our commission can't as much buy me a cup of cheap coffee without it being a violation. Yet we allow millions of people to vote for candidates who are committed in word and deed to increasing the size and spending of government, much of which directly benefits those voting government employees.
Second, I'd like to think that this might work to discourage people from taking positions with the government. I may not be the typical voter, but I'd sure think twice about signing up for a position if I knew that the acceptance of that position would cause me to be disenfranchised. Fewer government employees can be nothing but a good thing.
Third, and perhaps most importantly, we'd go a long way toward eliminating the pressure put on lawmakers to pander to government employees, teachers unions and the like with promises of more money in the relentless pursuit of votes. I don't doubt that the true big-government, big-spending legislators will still try to move forward their agenda, but those that are on the fence in tough districts would be more free to vote their conscience, and I'd like to think that without that pressure, their conscience would compel them to hold down the outflow of cash.