Do elections help control the scope of government or do they legitimize an increasing role for the public sector?
Elections only help to control the scope of government if the electorate wants a smaller government and is highly motivated by that desire. Up to this point, that has not been the case. We will see if the Tea Party movement is really strong enough and long-lived enough to change that.
You can clearly see that elections have not really controlled the scope of government because the size of our government has been constantly increasing even as we have continued to have elections. This increase has tended to continue through both Democratic and Republican governments.
Elections do not control the scope of government because this has not been anywhere near to the most salient issue to most voters. They would rather get the benefits of "pork" or vote based on social issues instead of voting to limit the scope of government.