The pushback in the early days of the 2020 campaign reflects the intensity Democrats are bringing to the race. The party is singularly focused on retaking the White House and anxious about any hurdle that would prevent them from seizing on Trump's unpopularity.
While no independent has won the presidency since George Washington, Democrats fear that Schultz would almost certainly split their vote and give Trump an easier path to re-election. Yet Democrats concede that they had few tools to dissuade Schultz from launching an independent campaign - as he told CBS' 60 Minutes on Monday that he was considering - though many were sceptical that he would actually follow through.
Schultz plans to spend the next month travelling around the country - in part promoting a new book - to test whether there's interest in an independent presidential candidate, according to a person familiar with his planning.
Schultz's team has polled on the viability of a third party run and believes there is an opening, though they have not shared the specifics of their internal surveys.
His advisers dispute the notion that an independent candidate would automatically bolster Trump's prospects in 2020, arguing that there are enough Democrats and Republicans disgruntled with their parties to propel a third-party bid.
Schultz addressed his prospects in a video posted on social media yesterday. "At this time in America when there's so much evidence that our political system is broken - that both parties at the extreme are not representing the silent majority of the American people - isn't there a better way?" Schultz said, noting that he'd be travelling the country in the coming weeks and months meeting with voters.
"And what better expression of our democracy than to give the American people a choice that they deserve."
Yet history - and the reality of a political system designed to favour major party candidates - suggests that Schultz may do little more than play spoiler should he decide to run. Michael Bloomberg, the billionaire former mayor of New York City who studied the possibility of an independent run of his own in the past, offered Schultz a direct message based on his own experience.
"The data was very clear and very consistent. Given the strong pull of partisanship and the realities of the electoral college system, there is no way an independent can win. That is truer today than ever before," Bloomberg, who is considering a Democratic 2020 bid, said.
He continued: "In 2020, the great likelihood is that an independent would just split the anti-Trump vote and end up re-electing the President. That's a risk I refused to run in 2016 and we can't afford to run it now."
The angry voices were far and wide, and they included Obama's former chief strategist, David Axelrod, along with Democrats from Schultz's home state.
"If Schultz decides to run as an independent," Axelrod tweeted, Trump "should give Starbucks their Trump Tower space rent free! It would be a gift." Tina Podlodowski, the Democratic chairwoman in Washington state, where Schultz has lived for decades, discouraged him from running as an independent.
"A billionaire buying his way out of the entire primary process does not strengthen democracy," she said. "It only makes it more likely that our democracy will be further strained under another four years of President Donald Trump."
Perhaps trying to elevate Schultz, who is not well known among Democratic primary voters, Trump himself weighed in yesterday, tweeting that Schultz "doesn't have the 'guts' to run for President!"
- AP