One reason dishonesty is so prevalent in politics is that there is a gap what politicians promise and what they can actually deliver. Politicians do not have much incentive to be honest about the limitations of government, because they derive political advantages from leading voters to believe their wishes can be fulfilled.
This dishonesty is one reason both state governments and the federal government are in budgetary crises. Obviously, the primary reason for these budgetary crises is the ongoing Great Recession, which has simultaneously decreased government revenues while increasing the demand for government services. However, politicians have exacerbated the crisis by using borrowing to fuel the fantasy that it is possible to have low taxes and effective public services. And, oh, by the way, it’s all going to be done while fighting two foreign wars and dramatically increasing the defense budget.
Voters complain about the dishonesty of their leaders, but successful politicians come to understand that there are some issues–such as budgeting–for which dishonesty is safer than honesty.
This point holds, by the way, not just for proponents of government spending. Proponents of small government also have an incentive to exaggerate the extent to which the budget can be cut without doing damage to services their constituents value. They have an incentive to exaggerate the role of earmarks on government spending; they have an incentive to exaggerate the budgetary effects of the notoriously vague “waste, fraud and abuse;” and they have an incentive to exaggerate the extent to which government programs imperil liberty.
The fact is that politicians benefit from promising more than they can deliver. Sure, they will inevitably fail to deliver on their promises, but, by that point, they may have already been re-elected. If not, they can always put the blame on those villainous Democrats or Republicans who “despite my great efforts to the contrary, just wouldn’t do what’s right for the country.”