George Will, a Pulitzer Prize–winning conservative journalist who ripped up his Republican card this year after Donald Trump's nomination, says a narrow GOP defeat would be "the worst conceivable outcome" for the party.

FBI Director James Comey's announcement of the discovery of possibly new Hillary Clinton emails last Friday appears to have shaken up national polls, narrowing the gap between the two candidates. But Will said a narrow defeat would fuel "the old stab-in-the-back theory," with party members blaming Trump dissenters like House Speaker Paul Ryan and Nebraska Sen. Ben Sasse for dividing Republicans.

Will, a columnist for The Washington Post, argued that a landslide win for Clinton would help Republicans by giving the party room to distance itself from divisive candidates and from the "indignation industry," as he dubbed it, of talk radio and cable personalities.

Speaking to ABC News' Jonathan Karl and Rick Klein on the "Powerhouse Politics" podcast today, Will said he was doubtful of a Republican win, barring fundamental changes in the party, starting with how Republican radio and talk show hosts speak about certain issues and groups.

"Until the Republican Party gets right with minorities in this country," Will said, "it's never going to win another presidential election."

He said, "The party has to look at its nominating process. It must never again have debates with 12 people onstage at a time."

"I don't know what you do to erect a kind of filter to keep a certain kind of candidate off the stage, but they have to work on their nominating process," he added.

Known for referring to baseball in his columns, Will said of the 23 percent chance that FiveThirtyEight's Nate Silver estimates both Trump and the Chicago Cubs have of winning this year, "I think he's underestimating the Cubs and overestimating Donald Trump."

Will said Comey's announcement about the review of possibly new Clinton emails was reckless, arguing that he broke FBI protocol for the wrong reasons.

"He sends this letter to Congress, saying emails of unknown content and unknown prominence might be 'pertinent' — that's a word to watch for here — to the prior Clinton investigation," Will said. "Something can be pertinent without being significant. That is, it could be pertinent in the sense that it's redundant evidence of what we already know, which was that she was, in Comey's language, 'extremely careless' in handling sensitive materials."

"This is not news people can use," Will continued. "It's of no help to voters. And it's of no help to anyone, so far as I can see."

"It's an old saying our grandmothers told us — don't talk unless you can improve the silence," he added. "I don't think he did."

While pundits and party leaders alike have been calling for updates from Comey in the investigation or a clarification of the wording in his letter, Will said, "That makes it worse, although his silence is bad enough, that could make it worse."

Some 20 million votes have already been cast, Will noted, and at just one week before the nation's decision day, he advised, "I think silence would be golden at this point."