Sometimes events reshape a presidential campaign. Sometimes they reshape the world the candidates seek to lead.

This week's Wall Street earthquake is such a big event that it is doing both. Much chatter is being devoted to how the market tremors are affecting the campaign -- whether they help Sen. Barack Obama by reinforcing his "change" message, whether Sen. John McCain has hurt himself with his initial declaration that the fundamentals of the economy remain sound, and so forth.

Here's...