No Problem With Ma As KMT Chief?

Should presidents (or prime ministers) of democratic countries accept dual roles as chairmen of their parties as well?  It's a question I confess not having thought much about, but I suppose that if the posts are held by different people, the line is more clearly demarcated between party and state affairs.

Dr. William Fang of the China Post believes the opposite , arguing that Taiwanese president Ma Ying-jeou should, in addition to his current job, become chairman of the Chinese Nationalist Party as well:

First it must be noted that in advanced democracies such as the United States and Great Britain, heads of the parties in power are also the highest administrative leaders of these countries.  No one accuses these rulers of being power-thirsty because they use their power [while simultaneously holding these two jobs] prudently and wisely to advance the interests of their nations.  [emphasis added]

The strength of Fang's case is unfortunately weakened by the fact that he's flat-out wrong.  America's president is currently Barack Obama (from the Democratic Party) -- but the chairman of the Democratic party is not Obama:  It's Virginia Governor Tim Kaine.

As for Great Britain, its current prime minister is Gordon Brown (of the Labour Party).  But the chair of the Labour Party is not Brown:  It's a woman named Cathy Speight (to verify, click here and scroll down a couple of pages).

Now, perhaps there ARE examples of democratic countries where politicians successfully juggle roles as executives of both the party and the state.  America and the U.K. however, are not countries on that list.