NEW YORK - Watch Bill O'Reilly and Keith Olbermann on the same night and you'll swear they're talking about two different presidential campaigns.

At 8 o'clock each weeknight, the two men survey the McCain-Obama competition from opposite mountaintops, as kings of cable's opinion class. They're the beneficiaries of an increased desire by news viewers to follow stories through their own ideological filters.

Things may quiet down after Election Day, but that trend likely won't be reversed.

O'Reilly, who last week announced he'd signed a multiyear contract to stick with Fox News Channel, is on pace to have his third most-watched month ever with 4 million viewers a night. September was second.

Olbermann has hit milestones this month - on Oct. 14 his largest audience since “Countdown” started in April 2003, and on Tuesday his biggest in a key youthful demographic.

Together with Rachel Maddow, MSNBC's liberal two-hour block is averaging just under 2 million viewers a night this month, compared to the 576,000 for Olbermann and Dan Abrams in October 2007, according to Nielsen Media Research.

During a “typical” night on Wednesday, Olbermann and O'Reilly's agendas rarely intersected, except when discussing news that the Republican Party had spent $150,000 in clothes and accessories for Sarah Palin and her family from high-end stores like Saks Fifth Avenue and Neiman Marcus.

Olbermann made it the subject of his commentary, saying the American public had “completely seen through” the McCain campaign.

“Nothing could say disconnect faster - you trying to pin your opponent with the phrase ‘share the wealth,' while your campaign gets pinned for having shared $150,000 of wealth with two of the ritziest clothing stores in the country to dress up your running mate,” Olbermann said.

O'Reilly and his guest, Laura Ingraham, condemned NBC News for reporting about the spending (“they're a joke,” Ingraham said). She said the same people critical of the spending would say Palin looked like “white trash” without the new clothes.

“Sarah Palin has adopted Barack Obama's campaign mantra,” O'Reilly said. “She is spreading the wealth around.”

Ingraham broke up in laughter.

The increased popularity of the opinionated shows has one newsman concerned about viewers retreating into their own cocoons. People need to be challenged with different views, and they're likely to have fewer opportunities to do so with programs like “Countdown” and “The O'Reilly Factor” making money for their networks, said Rome Hartman, executive producer of BBC's “World News America.”

Flipping back and forth between Olbermann and O'Reilly would be enough to give most viewers whiplash.

Doubtlessly, few try.