(CNN) If you want to understand the divisions roiling the Democratic party, look no further than its ongoing "unity tour."

Vermont Sen. Bernie Sanders and new Democratic National Committee Chairman Tom Perez are on the road, barnstorming the country as part of a campaign to rally resistance against President Donald Trump and -- in theory -- make a public display of their common cause.

The early returns have not been promising. At a kick-off event in Maine on Monday, the audience roared for Sanders and booed at the mention of the DNC. A night later, Perez and Sanders sat together for a joint interview on MSNBC.

Sen. Bernie Sanders and DNC Chair Tom Perez walk past each other as Sanders takes to the stage to speak during their "Come Together and Fight Back" tour at the James L Knight Center on April 19, 2017 in Miami, Florida.

"Do you consider yourself a Democrat?" host Chris Hayes asked the Vermont senator.

"No, I am an independent," Sanders replied, before launching into a lengthy explanation of what ailed the party -- whose nomination he sought in 2016 -- and what it needs to do in order to reclaim power.

Hayes then turned to Perez with a question on single payer health care, or "Medicare-for-all." Did the new DNC chair, now twisting in his seat inches from one of the policy's most high-profile proponents, support it?

"Well, you know, we want to make sure that health care is a right," Perez began, never quite offering a coherent answer.

And so it's been and so it goes for Democrats in the age of Trump. The moderate wing of the party -- derisively termed "liberals" by those further left -- is loath to give over power to the progressive insurgency, which holds up Democratic nominee Hillary Clinton's loss as proof Democrats needs to fundamentally remake -- and elevate -- their economic message.

The stalemate threatens the party's prospects in 2018 and portends a bloody presidential primary ahead of the 2020 general election.

That's why Perez, fresh off a contentious campaign to take over the DNC, is sharing a stage and sitting down for joint interviews with Sanders. The former Obama administration labor secretary, an accomplished progressive in his own right, is the establishment figure in this set-up. Sanders, as always, is the firebrand, though now he comes with a power base of passionate supporters the party is desperate to win over.

To the establishment liberal wing, Sanders' screeds come off as something between grating and condescending. Why, they ask, is someone who refuses to identify as a Democrat, being given so much say in the party's future? The nerve!

On the flip side, many progressive Democrats regard Sanders, along with a few others, like Massachusetts Sen. Elizabeth Warren, as the left's answer to the corporate influence -- and political incompetence -- it believes poisoned Clinton's candidacy. They view Sanders as a uniquely powerful bulwark against the party's embrace of policies (free trade, austerity, privatization, etc.) they despise.

Sanders has not been shy in making the argument.

"Donald Trump did not win the election -- the Democrats lost the election!" he said (again) during an event in Miami on Wednesday night. "That means rebuilding the Democratic Party, making it a grassroots party, a party from the bottom on up!"

Perez might agree. Or not. Either way, his job is more complicated. The DNC, more than a policy shop, is a massive political organization dedicated to raising money and making choices about where to allocate it in the service of electing as many Democrats as possible. Now, that decision-making process is obviously tied in to its own values, but winning is the clear priority. Should he push progressive candidate who supports all the party's core values -- and what are those core values? -- or a more moderate candidate better suited to a specific location?

These fault lines are hardly new, but they were magnified after Clinton lost to Trump in November -- a result that was more roundly shocking than the Sanders brigade, which has made a meme of its claim that "Bernie would have won," might currently let on.

On the eve of the election, it was not just large segments of the political media and Clinton supporters and allies who expected her to win. Leading progressive activists, many of them Sanders backers, were confident, too, and expressed optimism, at least in private, that a Clinton administration would provide them with a seat at the table.

A day after the vote, their best laid plans in tatters, the more organized elements of the progressive resistance begin to mobilize. Though mostly decentralized, it generally focused on two common goals: turn back President Trump's agenda and remake the Democratic Party in a way that would make it more appealing to working class voters.

On the first count, the movement has been remarkably successful. Progressive pressure, from the streets to the halls of Congress, stiffened the backs of elected officials who, in the early days of the new administration, signaled a cautious willingness to do business with Trump.

Blowback against the GOP's Obamacare overhaul was strict and wicked. The bill, thanks in part to Republicans' own internal divisions, never made it to the House floor. Senate Democrats forced Republicans to "go nuclear" with their filibuster of Supreme Court Justice Neil Gorsuch's nomination.

But the latter charge -- charting a course forward for Democrats -- has been much more complicated and, if only in the space of a few months, plainly less successful.

That's the history. Whether the party is able to confront it and negotiate the future in goodwill is less certain. The first days of the Sanders-Perez "unity tour" suggest the conversation has yet to really begin.