NEW YORK (AP) – Still reeling from Tim Russert's death, NBC News must now contemplate replacing the man who not only dominated the Sunday morning talk shows, but served as chief political commentator and ran the Washington bureau.

The "Meet the Press" host had what was arguably the most important and far-reaching job in television news, particularly in an election year. He died of a heart attack on Friday while preparing for another week's edition of "Meet the Press''.

NBC wasn't talking about potential successors while planning Russert's wake yesterday and memorial service today that will be televised on MSNBC from the Kennedy Center in Washington, DC. Top anchor Brian Williams cancelled an appearance on Monday at the Peabody Awards to be with his stricken staff.

NBC has potential successors to Russert on "Meet the Press" already within the company. The decision has big financial implications, since the show reportedly earns more than $60 million a year in profits with relatively few expenses and often has a waiting list of potential advertisers.

A wrong move can provide an opportunity to ABC News' "This Week" and George Stephanopoulos, which has averaged 2.8 million viewers this year. That's second to NBC's 4.17 million, with both networks up from last year during a period of heavy political attention.

"Hardball" host Chris Matthews is the best-known internal candidate. He already has a Sunday talk show syndicated by NBC Universal that's very competitive with the networks, despite taping on Friday.

"The Chris Matthews Show" averages about 2.3 million viewers, less than CBS' "Face the Nation" and more than Fox's show with Chris Wallace.

Matthews was considered a candidate to replace Bob Schieffer on "Face the Nation" earlier this year, until Schieffer decided to stay on a few more years.

Matthews, a relentless talker, would have to change his style to fit in to Russert's "Meet the Press" reportorial template. Along with MSNBC's "Countdown" with Keith Olbermann, he represents an opinionated style that would change the course of the show, and already caused controversy this political season by saying Hillary Clinton became a senator and a candidate for president because "her husband messed around''.

Matthews' long history of strong opinions is in stark contrast to Russert's nimble, middle-of-the road approach – and could be reason enough for NBC to look elsewhere. And moving Matthews to "Meet the Press" would likely end his syndicated show, another disincentive to NBC.

Washington hands David Gregory and Andrea Mitchell are lesser-known, but fit into the objective reporting format that made "Meet the Press" with Russert the first stop for Washington newsmakers. Outsiders Gwen Ifill of PBS' "Washington Week'', a former NBC correspondent, and CNN's John King could fit the same mold.

There's some sentiment within NBC News to have Williams or retired anchor Tom Brokaw – who filled in this past Sunday – to sit in temporarily, perhaps through the election. That course would give NBC the chance to find a new host and build a format around that person's strengths outside the crucible of an election season.

But that could impose a brutal seven-day-a week schedule on Williams and keep the semi-retired Brokaw busier than he'd like to be.

Russert was a fixture beside first Brokaw, then Williams, on election nights with his contagiously enthusiastic analysis. He was a frequent guest of the "Today" show, explaining the latest political developments. His loss likely means a larger on-air role for Chuck Todd, the network's political director, who was recruited to NBC News by Russert. Todd has been increasingly visible this political season, particularly on MSNBC.

For all that Russert did onscreen, his job as Washington bureau chief was also vital. Wendy Wilkinson was Russert's chief deputy there, but no one came close to his role for all things political.