My column today in the New York Post says what happens on November 2 on a national scale is already baked in the cake; nothing that happens in the last week is going to make much of a difference (barring a huge event):

We’ve had 18 months of data points from many different sources that all tell the same story: Americans who vote have radically changed direction when it comes to which party they prefer. In both 2006 and 2008, voters said they preferred Democrats by margins of 8 to 12 points, and on Election Day handed Democrats landslide victories. But Republicans have led in the so-called “generic polls” since March 2009 without letup — and the gap between the two parties has remained stable at a level comparable to the previous Democratic advantage.

This means that, probably at minimum, 16 percent of the electorate has shifted from voting Democrat to declaring its intention to vote Republican. That is an astonishing degree of change, and it’s why you’ve heard so much talk about this being an unprecedented election.

Remember that the 1994 election, when Republicans seized control of Congress in the biggest midterm victory of the modern age, came after a presidential year in which the Democrat had gotten only 43 percent of the vote. The two non-Democrats combined for 57 percent in 1992. In hindsight, the prospect for a gigantic GOP victory in 1994 was evident.

But this midterm is coming after a Democrat won 53 percent of the vote in 2008. The buyer’s remorse on the part of those independents and Republicans who thought they’d give Barack Obama a shot is something entirely new.

And that buyer’s remorse is not momentary or sudden. The shift began 18 months ago. The trend line has been stable and long-lasting. Nothing from spring 2009 to autumn 2010 has come along to alter the trajectory. It is almost impossible that something will do so in the next seven days.

You can read the whole thing here.