"A party of order or stability, and a party of progress or reform, are both necessary elements of a healthy state of political life." John Stuart Mill, On Liberty, 1859. Political parties have often been portrayed in the popular media as corrupt or incompetent and are frequently viewed as the cause of government gridlock or the failure of democratically elected governments to deal with urgent issues. Political parties may become vehicles for powerful economic interests seeking to dominate the political process for their own private interests or serve as the basis for anti-democratic ideologies, such as fascism or communism, that seek political control over the society. Such negative manifestations of political parties, however, do not negate their essential importance as representative institutions in a democracy, nor the positive impact they may have within them. Political parties are the indispensable vehicles for citizens to engage in the democratic process — no modern...