Don Fowler, who served as chairman of the Democratic National Committee in the mid-1990s, is calling for the party to come up with a more detailed plan on picking a successor to presidential nominee Hillary Clinton should the need arise, Politico reported Monday.

That plan should be put in place quickly – as in 6 p.m. Monday – Fowler insisted earlier in the day. That deadline passed without a public announcement of any changes.

Fowler said he expected Clinton, whom he has supported ever since her first run for president in 2008, to fully recover from what her doctor said Sunday is a bout of pneumonia, but the process should be streamlined just in case it is ever needed.

"Now is the time for all good political leaders to come to the aid of their party," said Fowler. "I think the plan should be developed by 6 o'clock this afternoon."

Fowler's sense of urgency is reportedly mirrored by other party bigwigs.

Cokie Roberts reported Monday on NPR's "Morning Edition" that Clinton's health scare Sunday, when she appeared to faint after having to leaving 9/11 memorial activities in New York, has many Democrats concerned. Clinton canceled a planned fundraising event Monday in California.

"It's taking her off of the campaign trail," Roberts said. "It has them very nervously beginning to whisper about her stepping aside and finding another candidate."

David Shuster, a former MSNBC and Al Jazeera America anchor, tweeted an emergency DNC meeting is coming this week to consider a replacement, and they likely would pick Vice President Joe Biden.

Clarification from dem operatives @HillaryClinton pneumonia: Expect emergency DNC meeting to CONSIDER replacement. #HillarysHealth — David Shuster (@DavidShuster) September 11, 2016

DNC delegate: If @HillaryClinton withdraws, every indication now committee will vote to replace with Biden. @BernieSanders team scrambling — David Shuster (@DavidShuster) September 12, 2016

But Fowler told Politico, while rules currently exist to replace a candidate, he worries chaos could ensue if they are not made more clear.

"It's something you would be a fool not to prepare for," he said, adding Clinton should be careful not to get back on the trail too quickly.

"She better get well before she gets back out there because if she gets back out there too soon, it might happen again," he said.

In any case, Clinton cannot be ousted from her nomination against her will. She would have to voluntarily give up the role if she felt unable to continue.

Current rules say the DNC chair must call a special meeting to decide upon a replacement. Chairwoman Debbie Wasserman Schultz resigned just ahead of the Democratic Convention his summer, so that role would go to acting Chairwoman Donna Brazile.

"The locus of activity for all of those political questions would then move to the 447 members of the Democratic National Committee," veteran DNC Rules Committee member Elaine Kamarck told Politico. "And it's wide open, and all of the political concern would work out in the context of discussions among the members of the DNC."

Proxy votes would not be allowed.

Fowler wants something more detailed, including requiring signatures for those nominated and nominations being made during the DNC's meeting. That would give voters more confidence in the process and help the party rally around the replacement nominee, he said.

"There should be a concerted, unified effort on behalf of the president and the Democratic leaders in the House and the Senate and from the officials of the DNC as well – I think unanimity would be absolutely critical," he said. "The quicker that unanimity develops, the easier and better the process."

The current process has been in place for decades, and has not been used since 1972, when George McGovern's vice presidential running mate Thomas Eagleton was forced to quit for mental health concerns. Sargent Shriver was named his replacement.

Shriver's nomination went smoothly, but a change at the top of the ticket might not, many fear, especially in what has been a contentious year.

Vermont Sen. Bernie Sanders, who had a loyal following and who fought Clinton till the bitter end, might have supporters. Others favor Biden, and some might feel Clinton's running mate Tim Kaine should get the nod.

Also, many states already have passed the deadline to have names on their Nov. 8 ballots.

But that should not be a problem, Karmack, the Rules Committee member, told Politico. After all, the president is actually elected in December by the Electoral College.