Not from The West Wing executive producer John Wells, though. He seems unfazed by the coming end of Democratic President Josiah "Jeb" Bartlet's tenure - and maybe even a Republican successor.

"We were a year and a half into the administration when we started the show," Wells says of the NBC drama entering its sixth season. "We have term limits in this country and so, on our electoral schedule, Bartlet's second term would end a year from this coming January."

That fact foreshadows a hybrid season when The West Wing returns (9 p.m. Wednesday, Channels 5, 2). Bartlet (Martin Sheen) grapples with his legacy while others fight for the chance to replace him.

Among them are contenders played by two familiar actors: Jimmy Smits (NYPD Blue), who's a potential Democratic candidate, and Alan Alda (M*A*S*H) vying for the GOP nomination.

Also in the running is Vice President Russell (Gary Cole), with talented staff member Will Bailey (Josh Malina) at his side.

Could Wells envision The West Wing, if re-elected by NBC to a seventh season, with a Republican president?

"I really could," he said. "What we've tried to put forward in the Bartlet administration is a Democratic presidency that was a bit of wish-fulfillment of what you'd really want your Democratic president to be.

"I don't think there's any reason you wouldn't want to see that show with a Republican."

Is he concerned that the show, called "The Left Wing" by those who find Bartlet's politics grating, might be seen as making the move to pander to conservatives?

"I think it depends on who the Republican candidate is and how you feel about the candidate by the time he or she is elected," he said.

A new commander-in-chief, from either party, would mean wholesale changes in the White House staff and the cast.

Before the NBC show wades into the heat of primary contests and before Bartlet gives up power, there are issues to resolve.

At the end of last season, growing violence in the Middle East led to the death of prominent U.S. officials and left an angry Bartlet weighing military action - and now trying to revive the Israeli-Palestinian peace process.

The Gaza Strip attack also critically injured White House staff member Donna Moss (Janel Moloney), who was part of the American contingent.

Whether Donna survives (and whether she and her boss, deputy chief of staff Josh Lyman, finally become an item) are obvious cliffhangers. Wells promises other immediate upheaval in The West Wing.

"There are substantial changes in the White House at the beginning of the season, within the first two episodes," Wells said.

After the dust settles, the latter part of the season will focus on the campaign trail with Smits' and Alda's characters and on how Bartlet delivers his swan - or lame-duck - song.

"How does the Bartlet administration deal with the remaining time they have in trying to be effective?" Wells said. "What does he really want to accomplish in his remaining year in office?"