Andrew Malcolm: These Democratic presidential debates are very important � until the next ones

At its 243rd birthday, the United States has a proud and widely-admired political tradition of freedom and generally democratic elections of its own leadership.

Thanks to voters' brief episodic attention spans and earnest but shallow media coverage that treats a leadership choice like some marathon Kentucky Derby, the United States has a presidential selection process that's a mess.

It is raucous and familiar to most of us and may be better than many other leadership selections. But it's based on superficial TV impressions, stereotypes, money, quips, empty hopes and complete happenstance.