Independent voters make up about a quarter of the electorate, and a recent poll shows them divided about evenly this year -- 44% are for Barack Obama and 41% for John McCain.

In some years that wouldn't be a big deal for McCain, but this year it is. Democrats decisively outnumber Republicans and one GOP pollster admits McCain needs to win a majority of independents if he's going to win the White House.

During the primaries, independents were a strength for both contenders.

But lately, independents are sounding more like Democrats than Republicans on what's become the dominant issue in the campaign: the teetering economy. Like Democrats and unlike Republicans, most independents said they'd prefer a candidate they trust to handle the economy to one they trust on national security.