Something like 230,000 Alaskans appear to have cast ballots in this month's midterm election, compared with fewer than 146,000 who voted in the Republican and Democratic primaries combined. A CNN/Time poll in the weeks before the election showed Ms. Murkowski edging Mr. Miller among independent voters, even though she wasn't actually on the ballot.

What all of this probably means is that some critical number of independent voters decided they didn't like the options the two parties had given them, and they were willing to go to the trouble of writing in a candidate who seemed to have a real chance of winning rather than pull levers A or B. ...

That number has risen steadily, however, especially among younger voters, to the point where independents have recently overtaken both parties, hovering around 40 percent. A recent Pew Center poll found that the number of voters who identified themselves as independents had risen five percentage points since 2002.

You have to wonder, given this trend, whether the primary process as we've known it can remain tenable. With each passing year, it seems, an ever smaller group of voters in either party -- rallying, in a year like this one, around ever more extreme points of view -- get to effectively determine the options for the rest of the electorate.